McCoy was later ruled out. X-rays on his ankle were negative, a source told ESPN's Adam Schefter.
McCoy injured the ankle while being tackled after a 3-yard run. He was helped to his feet by trainers before appearing unsteady, leading for the medical staff to call for a cart to take him to the locker room. Before the injury, McCoy ran 11 times for 10 yards.
McCoy was replaced in the backfield by Marcus Murphy, whom the Bills signed off their practice squad Tuesday. Murphy ran for a 25-yard gain in the first quarter.