He got nailed in the stomach.
I'm betting the emotions of the game, his exhaustion, and probably multiple gulps of gatorade led to this pukefest.
Of course, Matt, Matt, Matt Millen jumped right to hyperbole and said, "puking is the #1 sign of a concussion." No, fuckhead, it's not. Just like Laquon Treadwell isn't Dez Bryant, Michael Irving, and Barry Sanders combined.