Buffalo Bills running back LeSean McCoy left in the first quarter of Sunday's 37-5 loss to the Indianapolis Colts after suffering a head injury, the team announced.
Coach Sean McDermott confirmed McCoy is in the concussion protocol after the game.
McCoy was injured after he was hit out of bounds on a 1-yard run on Buffalo's opening drive. He was on the ground briefly before walking into the sideline medical tent under his own power. He was then accompanied by a trainer to the Bills' locker room.
The injury came with Derek Anderson making his Bills debut at quarterback in the wake of Josh Allen's elbow injury. Chris Ivory and Marcus Murphy filled in for McCoy, who has rushed for 243 yards in five games this season.
McCoy has been the subject of trade speculation in recent weeks ahead of the Oct. 30 trade deadline. While the Philadelphia Eagles are among the teams that have expressed interest in McCoy, NFL Network Insider Ian Rapoport reported last week there's a good chance the running back remains with the team in 2019.