MINNEAPOLIS, MN - NOVEMBER 29: Running back Adrian Peterson #28 of the Minnesota Vikings reaches for the football as linebacker Hunter Hillenmeyer #92 of the...

...Minnesota Vikings running back Adrian Peterson (28) prepares for a hit from Chicago Bears safety Al Afalava (24) during the first quarter...

Minnesota Vikings running back Adrian Peterson (28) and receiver Visanthe Shiancoe (81) celebrate Peterson's fourth-quarter touchdown against the Chicago Bears...

Minnesota Vikings running back Adrian Peterson (28) scores a fourth-quarter touchdown against the Chicago Bears, including Danieal Manning (38), during their...

Minnesota Vikings running back Adrian Peterson (28) prepares for a hit from Chicago Bears safety Al Afalava (24) during the first quarter...

Minnesota Vikings running back Adrian Peterson (28) runs against the Chicago Bears in the first quarter of an NFL football game Sunday...

Dec. 14, 2008; Glendale, AZ, USA; Minnesota Vikings running back (28) Adrian Peterson against the Arizona Cardinals at University of Phoenix Stadium. Mandatory Credit: Mark J. Rebilas-US PRESSWIRE...

...Photo by David Stluka/Getty Images) December 7, 2008; Detroit, MI, USA; Minnesota Vikings running back Adrian Peterson (28) runs for a first down in the third quarter against the Detroit Lions at Ford...

MINNEAPOLIS - NOVEMBER 30: Adrian Peterson #28 of the Minnesota Vikings carries the ball during an NFL game against the Chicago Bears...

...Ford Field. Mandatory Credit: Leon Halip-US PRESSWIRE 2-30 November 2008: Minnesota Vikings running back Adrian Peterson (28) slices through a hole in the Bears defense. The Minnesota Vikings defeated the Chicago Bears...

Minnesota Vikings running back Adrian Peterson, left, gains 3 yards before Chicago Bears linebacker Nick Roach, right, trips him up in the...

...Buccaneers in overtime at Soldier Field. Nov. 23, 2008; Jacksonville, FL, USA; Minnesota Vikings running back Adrian Peterson (28) heads up field during the second half of the Vikings 30-12 win over the...

...Todd Kirkland/Icon SMI 2- Oct 6, 2008; New Orleans, LA, USA; Minnesota Vikings running back Adrian Peterson (28) runs past New Orleans Saints defensive end Will Smith (91) during the second half at...

...14: Ade Jimoh #35, Anthony Adams #95 and Brendon Ayanbadejo #94 of the Chicago Bears stop Adrian Peterson #28 of the Minnesota Vikings on October 14, 2007 at Soldier Field in Chicago, Illinois. (Photo...

Dec 17 2007; Minneapolis, Minnesota, USA: Minnesota Vikings running back (28) Adrian Peterson runs against the Chicago Bears in the second quarter at the Metrodome