The Patriots placed rookie running back Jeff Demps on injured reserve Friday.
The team did not specify whether Demps has been placed on season-ending injured reserve or the new shortened injured reserve, where a player could return later in the season.
Demps was signed on Aug. 17. In the fourth quarter of Wednesday's preseason finale, he came up limping after a tackle and had his knee/ankle checked out on the sideline.
He didn't return to the game, but said in the locker room that he was OK.
Demps, the Olympic silver medalist, offered a potentially explosive element to the Patriots' return game. He also projected to add depth at running back.