Vikings RB Adrian Peterson left Saturday's game with an apparent left knee injury. He was helped off the field in the third quarter.
Peterson had 12 carries for 38 yards and a touchdown. He missed time earlier this season with an ankle injury. The 2-12 Vikings were tied with the Redskins when Peterson left the game.
Rookie QB Christian Ponder left the game as well after suffering a concussion. He will not return. Joe Webb will take over at quarterback.