It's now official. Washington Redskins running back Tim Hightower has a torn ACL and will miss the rest of the 2011 season, according to coach Mike Shanahan. Shanahan announced the news in his Monday press conference, which is streaming live on ESPN 980. Hightower will be placed on injured reserve immediately.

Hightower suffered the injury in the third quarter of the Redskins' 33-20 loss to the Carolina Panthers on Sunday, when his knee buckled trying to make a cutback. He did not return to the game.

Hightower had been very solid for the Redskins this season, rushing for 321 yards and one touchdown in five games while also doing a good job in blitz pickup. His absence means the Redskins will need to rely on Ryan Torain and Roy Helu to pick it up on the ground game. Hightower was acquired by the Redskins from the Arizona Cardinals in the offseason for defensive lineman Vonnie Holiday and a conditional draft pick.

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