INDIANAPOLIS -- Detroit Lions running back Theo Riddick left Sunday's game against the Indianapolis Colts to be evaluated for a concussion.
After undergoing tests for a possible concussion in the locker room, he was cleared to return in the fourth quarter.
In his first drive back in the field, Riddick caught a 13-yard pass to score the go-ahead TD for the Lions.
It's unclear when Riddick suffered the potential brain injury.
Riddick, who signed a three-year contract extension with the Lions on Friday, had three catches for 31 yards and five carries for 26 yards against the Colts.