Lamb was escorted off the field by trainers and into the medical tent for further evaluation during Thursday's game against the Lions, Todd Archer of ESPN.com reports.
Lamb went up for a jump ball in the end zone early in the third quarter and came down hard on his head and shoulder. The exact nature of the injury is unclear, though he's likely being evaluated for a concussion at a minimum. After spending a brief time in the medical tent, Lamb walked to the locker room.