UNITED STATES
                        SECURITIES EXCHANGE COMMISSION
                            Washington, D.C. 20549

------------------------------------------------------------------------------

                                 SCHEDULE 13G

                   Under the Securities Exchange Act of 1934
                               (Amendment No. )

                        RED ROBIN GOURMET BURGERS INC.
                        ------------------------------
                               (Name of Issuer)


                    Common Stock, par value $.01 per share
                    --------------------------------------
                        (Title of Class of Securities)


                                   75689M101
                                   ---------
                                (CUSIP Number)


                               December 31, 2006
                               -----------------
            (Date of Event which Requires Filing of this Statement)


Check  the  appropriate  box to  designate  the rule  pursuant  to which  this
Schedule is filed:

                               |X| Rule 13d-1(b)

                               |_| Rule 13d-1(c)

                               |_| Rule 13d-1(d)

* The  remainder  of this  cover  page  shall be  filled  out for a  reporting
person's  initial  filing on this form with  respect to the  subject  class of
securities,  and for any subsequent  amendment  containing  information  which
would alter the disclosures provided in a prior cover page.

The  information  required  in the  remainder  of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities  Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however,  see
the Notes).


                         Continued on following pages
                              Page 1 of 11 Pages
                            Exhibit Index: Page 11



                                 SCHEDULE 13G

CUSIP No.: 75689M101                                         Page 2 of 11 Pages

................................................................................
1.        Names of Reporting Persons.

          I.R.S. Identification Nos. of above persons (entities only).


          MAGNETAR FINANCIAL LLC
................................................................................
2.        Check the Appropriate Box if a Member of a Group

          (a) [  ]

          (b) [  ]
................................................................................
3.        SEC Use Only
................................................................................
4.        Citizenship or Place of Organization

          Delaware
................................................................................
Number of Shares      5.       Sole Voting Power                  1,244,049
Beneficially Owned    .........................................................
by Each Reporting     6.       Shared Voting Power                None
Person With           .........................................................
                      7.       Sole Dispositive Power             1,244,049
                      .........................................................
                      8.       Shared Dispositive Power           None
................................................................................
9.        Aggregate Amount Beneficially Owned by Each Reporting Person

          1,244,049
................................................................................
10.       Check if the Aggregate Amount in Row (9) Excludes Certain Shares
          (See Instructions)

          [  ]
................................................................................
11.       Percent of Class Represented by Amount in Row (9)

          7.50% based on 16,596,519 shares outstanding as of November 1, 2006.
................................................................................
12.       Type of Reporting Person:

          IA;OO





                                 SCHEDULE 13G

CUSIP No.: 75689M101                                         Page 3 of 11 Pages

................................................................................
1.        Names of Reporting Persons.

          I.R.S. Identification Nos. of above persons (entities only).


          MAGNETAR CAPITAL PARTNERS LP
................................................................................
2.        Check the Appropriate Box if a Member of a Group

          (a) [  ]

          (b) [  ]
................................................................................
3.        SEC Use Only
................................................................................
4.        Citizenship or Place of Organization

          Delaware
................................................................................
Number of Shares      5.       Sole Voting Power                  None
Beneficially Owned    .........................................................
by Each Reporting     6.       Shared Voting Power                1,316,439
Person With           .........................................................
                      7.       Sole Dispositive Power             None
                      .........................................................
                      8.       Shared Dispositive Power           1,316,439
................................................................................
9.        Aggregate Amount Beneficially Owned by Each Reporting Person

          1,316,439
................................................................................
10.       Check if the Aggregate Amount in Row (9) Excludes Certain Shares
          (See Instructions)

          [  ]
................................................................................
11.       Percent of Class Represented by Amount in Row (9)

          7.93% based on 16,596,519 shares outstanding as of November 1, 2006.
................................................................................
12.       Type of Reporting Person:

          HC;OO



                                 SCHEDULE 13G

CUSIP No.: 75689M101                                         Page 4 of 11 Pages

................................................................................
1.        Names of Reporting Persons.

          I.R.S. Identification Nos. of above persons (entities only).


          SUPERNOVA MANAGEMENT LLC
................................................................................
2.        Check the Appropriate Box if a Member of a Group

          (a) [  ]

          (b) [  ]
................................................................................
3.        SEC Use Only
................................................................................
4.        Citizenship or Place of Organization

          Delaware
................................................................................
Number of Shares      5.       Sole Voting Power                  None
Beneficially Owned    .........................................................
by Each Reporting     6.       Shared Voting Power                1,316,439
Person With           .........................................................
                      7.       Sole Dispositive Power             None
                      .........................................................
                      8.       Shared Dispositive Power           1,316,439
................................................................................
9.        Aggregate Amount Beneficially Owned by Each Reporting Person

          1,316,439
................................................................................
10.       Check if the Aggregate Amount in Row (9) Excludes Certain Shares
          (See Instructions)

          [  ]
................................................................................
11.       Percent of Class Represented by Amount in Row (9)

          7.93% based on 16,596,519 shares outstanding as of November 1, 2006.
................................................................................
12.       Type of Reporting Person:

          HC;OO



                                 SCHEDULE 13G

CUSIP No.: 75689M101                                         Page 5 of 11 Pages

................................................................................
1.        Names of Reporting Persons.

          I.R.S. Identification Nos. of above persons (entities only).


          ALEC N. LITOWITZ
................................................................................
2.        Check the Appropriate Box if a Member of a Group

          (a) [  ]

          (b) [  ]
................................................................................
3.        SEC Use Only
................................................................................
4.        Citizenship or Place of Organization

          United States of America
................................................................................
Number of Shares      5.       Sole Voting Power                  None
Beneficially Owned    .........................................................
by Each Reporting     6.       Shared Voting Power                1,316,439
Person With           .........................................................
                      7.       Sole Dispositive Power             None
                      .........................................................
                      8.       Shared Dispositive Power           1,316,439
................................................................................
9.        Aggregate Amount Beneficially Owned by Each Reporting Person

          1,316,439
................................................................................
10.       Check if the Aggregate Amount in Row (9) Excludes Certain Shares
          (See Instructions)

          [  ]
................................................................................
11.       Percent of Class Represented by Amount in Row (9)

          7.93% based on 16,596,519 shares outstanding as of November 1, 2006.
................................................................................
12.       Type of Reporting Person:

          HC



                                                            Page 6 of 11 Pages

Item 1(a).  Name of Issuer:

            Red Robin Gourmet Burgers, Inc. (the "Issuer")

Item 1(b).  Address of Issuer's Principal Executive Offices:

            6312 S. Fiddler's Green Circle, Suite 200N
            Greenwood Village, CO, 80111

Item 2(a).  Name of Person Filing:

            This Statement is filed on behalf of each of the following persons
(collectively, the "Reporting Persons"):

            i)    Magnetar Financial LLC ("Magnetar Financial")

            ii)   Magnetar Capital Partners LP ("Magnetar Capital Partners");

            iii)  Supernova Management LLC ("Supernova Management"); and

            iv)   Alec N. Litowitz ("Mr. Litowitz").

            This Statement  relates to Shares (as defined herein) held for the
accounts of Magnetar  Capital  Master  Fund,  Ltd, a Cayman  Islands  exempted
company  ("Magnetar  Capital  Master  Fund")  certain  managed  accounts  (the
"Managed  Accounts"),  Magnetar SGR Fund,  Ltd.  and  Magnetar  SGR Fund,  LP.
Magnetar Capital Partners serves as the sole member and parent holding company
of Magnetar  Financial,  and Magnetar Investment  Management,  LLC, a Delaware
limited liability company ("Magnetar Investment Management"). Each of Magnetar
Financial  and  Magnetar  Investment   Management  are  registered  investment
advisers under Section 203 of the Investment Advisers Act of 1940, as amended.
Magnetar  Financial  serves as investment  adviser to Magnetar  Capital Master
Fund. In such capacity,  Magnetar  Financial  exercises  voting and investment
power over the Shares held for the account of Magnetar  Capital  Master  Fund.
Magnetar  Investment  Management  serves as investment  adviser to the Managed
Accounts,  Magnetar SGR Fund, Ltd and Magnetar SGR Fund, LP. In such capacity,
Magnetar Investment  Management exercises voting and investment power over the
Shares held for the accounts of the Managed  Accounts,  Magnetar SGR Fund, Ltd
and Magnetar SGR Fund,  LP.  Supernova  Management  is the general  partner of
Magnetar  Capital  Partners.  The  manager  of  Supernova  Management  is  Mr.
Litowitz.

Item 2(b).  Address of Principal Business Office or, if None, Residence:

            The address of the principal  business  office of each of Magnetar
Financial,  Magnetar Capital Partners,  Supernova Management, and Mr. Litowitz
is 1603 Orrington Avenue, 13th Floor, Evanston, Illinois 60201.

Item 2(c).  Citizenship:

            i)    Magnetar Financial is a Delaware limited liability company;

            ii)   Magnetar Capital Partners is a Delaware limited partnership;


                                                            Page 7 of 11 Pages

            iii)  Supernova   Management  is  a  Delaware  limited   liability
                  company; and

            iv)   Mr. Litowitz is a citizen of the United States of America.

Item 2(d).  Title of Class of Securities:

            Common Stock, par value $.01 per share (the "Shares")

Item 2(e).  CUSIP Number:

            75689M101

Item 3.     If This  Statement  is Filed  Pursuant  to  ss.ss.240.13d-1(b)  or
            240.13d-2(b) or (c), Check Whether the Person Filing is a:

            (a)  [ ]    Broker or dealer  registered  under  Section 15 of the
                        Exchange Act.
            (b)  [ ]    Bank as  defined in  Section  3(a)(6) of the  Exchange
                        Act.
            (c)  [ ]    Insurance  company as defined in Section  3(a)(19)  of
                        the Exchange Act.
            (d)  [ ]    Investment  company  registered under Section 8 of the
                        Investment Company Act.
            (e)  [X]    An  investment   adviser  in   accordance   with  Rule
                        13d-1(b)(1)(ii)(E);
            (f)  [ ]    An  employee   benefit  plan  or  endowment   fund  in
                        accordance with Rule 13d-1(b)(1)(ii)(F).
            (g)  [ ]    A  parent   holding   company  or  control  person  in
                        accordance with Rule 13d-1(b)(1)(ii)(G).
            (h)  [ ]    A savings  association  as defined in Section  3(b) of
                        the Federal Deposit Insurance Act.
            (i)  [ ]    A church plan that is excluded from the  definition of
                        an investment  company  under Section  3(c)(14) of the
                        Investment Company Act.

Item 4.     Ownership:

Item 4(a)   Amount Beneficially Owned:

            (i) As of February 5, 2007,  each of  Magnetar  Capital  Partners,
Supernova Management and Mr. Litowitz may be deemed to be the beneficial owner
of 1,316,439  Shares.  This amount consists of: (A) 1,244,049  Shares held for
the  account of  Magnetar  Capital  Master  Fund;  (B) 347 Shares held for the
account of  Magnetar  SGR Fund Ltd;  (C) 6,945  Shares held for the account of
Magnetar SGR Fund LP and (D) 65,098 Shares held for the account of the Managed
Accounts.

            (ii) As of February 5, 2007,  Magnetar  Financial may be deemed to
be the  beneficial  owner of 1,244,049  Shares.  This amount  consists of: (A)
1,244,049 Shares held for the account of Magnetar Capital Master Fund.

Item 4(b)   Percent of Class:

            (i) The  number  of  Shares  of  which  each of  Magnetar  Capital
Partners,  Supernova  Management  and Mr.  Litowitz  may be  deemed  to be the
beneficial owner constitutes approximately 7.93% of the total number of Shares
outstanding  (based  upon  information  provided  by the  Issuer  in its


                                                            Page 8 of 11 Pages

most  recently  filed   registration   statement  on  Form  10-Q,  there  were
approximately 16,952,094 shares outstanding as of November 1, 2006.

            (ii) The  number  of  Shares of which  Magnetar  Financial  may be
deemed to be the beneficial owner constitutes approximately 7.50% of the total
number of Shares outstanding.

Item 4(c)   Number of Shares of which such person has:

Magnetar Financial:

(i) Sole power to vote or direct the vote:                          1,244,049

(ii) Shared power to vote or direct the vote:                               0

(iii) Sole power to dispose or direct the disposition of:           1,244,049

(iv) Shared power to dispose or direct the disposition of:                  0
Magnetar Capital Partners, Supernova Management, and Mr. Litowitz:

(i) Sole power to vote or direct the vote:                                  0

(ii) Shared power to vote or direct the vote:                       1,316,439

(iii) Sole power to dispose or direct the disposition of:                   0

(iv) Shared power to dispose or direct the disposition of:          1,316,439


Item 5.     Ownership of Five Percent or Less of a Class:

            This Item 5 is not applicable.

Item 6.     Ownership of More than Five Percent on Behalf of Another Person:

            This Item 6 is not applicable.

Item 7.     Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on By the

            Parent Holding Company:

            See disclosure in Item 2 hereof.

Item 8.     Identification and Classification of Members of the Group:

            This Item 8 is not applicable.

Item 9.     Notice of Dissolution of Group:

            This Item 9 is not applicable.

Item 10.    Certification:

            By signing below each of the Reporting  Persons certifies that, to
the best of their knowledge and belief, the securities  referred to above were
not  acquired  and are not  held for the  purpose  of or with  the  effect  of
changing or  influencing  the control of the issuer of the securities and were
not


                                                            Page 9 of 11 Pages

acquired  and  are not  held in  connection  with or as a  participant  in any
transaction having that purpose or effect.



                                                           Page 10 of 11 Pages

                                   SIGNATURE

      After reasonable inquiry and to the best of my knowledge and belief, the
undersigned  certify that the information set forth in this statement is true,
complete and correct.

Date: February 14, 2007                  MAGNETAR FINANCIAL LLC

                                         By: Magnetar Capital Partners LP
                                             As Sole Member

                                         By:  /s/ Alec N. Litowitz
                                              -----------------------
                                         Name:  Alec N. Litowitz
                                         Title: Manager      of      Supernova
                                                Management   LLC,  as  General
                                                Partner  of  Magnetar  Capital
                                                Partners LP


Date: February 14, 2007                  MAGNETAR CAPITAL PARTNERS LP


                                         By:  /s/ Alec N. Litowitz
                                              -----------------------
                                         Name:  Alec N. Litowitz
                                         Title: Manager      of      Supernova
                                                Management   LLC,  as  General
                                                Partner  of  Magnetar  Capital
                                                Partners LP

Date: February 14, 2007                  SUPERNOVA MANAGEMENT LLC


                                         By:  /s/ Alec N. Litowitz
                                              -----------------------
                                         Name:  Alec N. Litowitz
                                         Title: Manager

Date: February 14, 2007                  ALEC N. LITOWITZ


                                         /s/ Alec N. Litowitz
                                         -----------------------



                                                           Page 10 of 11 Pages


                                 EXHIBIT INDEX


Ex.                                                                 Page No.
---                                                                 --------
A.       Joint Filing  Agreement,  dated February 14, 2007 by and
         among Magnetar  Financial LLC, Magnetar Capital Partners
         LP, Supernova Management LLC, and Alec N. Litowitz......     12



                                                           Page 11 of 11 Pages

                                   EXHIBIT A

                            JOINT FILING AGREEMENT

      The  undersigned  hereby  agree that the  statement on Schedule 13G with
respect to the Common Stock of Red Robin  Gourmet  Burgers,  Inc.  dated as of
February 14, 2007 is, and any  amendments  thereto  (including  amendments  on
Schedule 13D) signed by each of the  undersigned  shall be, filed on behalf of
each of us pursuant to and in accordance  with the provisions of Rule 13d-1(k)
under the Securities Exchange Act of 1934, as amended.

Date: February 14, 2007                     MAGNETAR FINANCIAL LLC

                                            By: Magnetar Capital Partners LP
                                                   As Sole Member

                                            By:  /s/ Alec N. Litowitz
                                                 --------------------
                                            Name:  Alec N. Litowitz
                                            Title: Manager     of     Supernova
                                                   Management  LLC,  as  General
                                                   Partner of  Magnetar  Capital
                                                   Partners LP


Date: February 14, 2007                     MAGNETAR CAPITAL PARTNERS LP


                                            By:  /s/ Alec N. Litowitz
                                                 --------------------
                                            Name:  Alec N. Litowitz
                                            Title: Manager     of     Supernova
                                                   Management  LLC,  as  General
                                                   Partner of  Magnetar  Capital
                                                   Partners LP

Date: February 14, 2007                     SUPERNOVA MANAGEMENT LLC


                                            By:  /s/ Alec N. Litowitz
                                                 --------------------
                                            Name:  Alec N. Litowitz
                                            Title: Manager

Date: February 14, 2007                     ALEC N. LITOWITZ


                                            /s/ Alec N. Litowitz
                                            --------------------