Bills running back LeSean McCoy was only two carries into Sunday's game against the Colts when he left the game after being upended. Although it was originally thought to be an ankle injury, it was announced that he had a head injury.
After watching the replay of the play that McCoy was injured on you can clearly see that he landed hard on his head.
We won't say the "c" word since the Bills made no mention of it, but that play had "c" word written all over it. We have to assume that he's being evaluated for one of those.