Lions' Thomas Harper: Questionable to play Sunday

Harper (concussion) is questionable for Sunday's matchup against the Rams, Eric Woodyard of ESPN.com reports.

Harper was a limited participant in all three practices heading into Week 15. The 25-year-old suffered a concussion in the Lions' Week 14 win over Dallas and will need to clear the league's five-step concussion protocol before having a chance to play Sunday against the Rams.