"Crunched for roster space by injuries to Matthew Stafford and Jason Hanson, the Detroit Lions placed running back Kevin Smith on injured reserve today and signed linebacker Caleb Campbell off the practice squad.

Smith injured his right thumb in the first half of last week's 14-12 loss to the Buffalo Bills when he took a helmet to the hand. He underwent surgery Thursday and said Friday he hoped to have his hard cast off and be in a splint by next week.

With Smith expected to miss several games, the Lions juggled their running back rotation in practice this week. Maurice Morris, who had been the personal protector on punt team, moves up the depth chart as Jahvid Best's backup. It's unclear what role Morris will play on special teams going forward.

Campbell, who was drafted in the seventh round out of Army in 2008 but not allowed to pursue a football career until this spring, traveled with the Lions (2-7) to Dallas and could play on special teams Sunday against the Cowboys."