MINNEAPOLIS - NOVEMBER 15: Adrian Peterson #28 of the Minnesota Vikings carries the ball during an NFL game against the Detroit Lions...

Nov 11, 2007; Green Bay, WI, USA; Minnesota Vikings running back Adrian Peterson (28) is attented to on the sidelines by team trainers after injuring his right knee during...

MINNEAPOLIS - NOVEMBER 15: Adrian Peterson #29 of the Minnesota Vikings carries the ball as Phillip Buchanon #31 of the Detroit Lions...

GREEN BAY, WI - NOVEMBER 01: Al Harris #31 of the Green Bay Packers tackles Adrian Peterson #28 of the Minnesota Vikings during the third quarter of the game at Lambeau Field on...

Minnesota Vikings quarterback Brett Favre celebrates after a touchdown by Vikings running back Adrian Peterson during the first quarter of an NFL football game against the St. Louis Rams Sunday, Oct...

SEATTLE - SEPTEMBER 27: Adrian Peterson #29 of the Chicago Bears carries the ball during the game against the Seattle Seahawks on...

Peterson's Power

Vikings RB Adrian Peterson runs over William Gay of the Steelers after taking a short pass from Brett Favre in...

Adrian Peterson discards William Gay during Minnesota's loss to Pittsburgh

Minnesota Vikings running back Adrian Peterson (28) runs in the NFL football game against the Pittsburgh Steelers in Pittsburgh, Oct. 25, 2009...

MINNEAPOLIS - SEPTEMBER 27: Adrian Peterson #28 of the Minnesota Vikings carries the ball during an NFL game against the San Francisco...

Oct 18, 2009; Minneapolis, MN, USA; Minnesota Vikings running back Adrian Peterson (28) rushes for 26 yards as Baltimore Ravens safety Ed Reed (20) pursues him in the...

Minnesota Vikings quarterback Brett Favre (4) hands the ball off to running back Adrian Peterson (28) during the first quarter of a NFL football game on Sunday, Nov. 22, 2009, against...

Minnesota Vikings running back Adrian Peterson, left, gains yardage on a pass-play before being brought down by Seattle Seahawks linebacker David...

Minnesota Vikings' Adrian Peterson, right, Detroit Lions linebacker Julian Peterson laugh on the field after an NFL football game Sunday...