Raiders wider receiver Amari Cooper was knocked from Sunday's game against the Broncos with a concussion following what an angry Oakland coach Jack Del Rio described as a "vicious hit."

Del Rio said after the game that Cooper was OK, though in the league's concussion protocol, but the Raiders coach clearly was upset with the hit that knocked his wide receiver unconscious in Sunday’s brawl-marred 21-14 victory.

“It was a vicious hit,” Del Rio told reporters (via NBC Sports Bay Area). “It’s the kind we’re trying to remove from our game, quite frankly. You see less and less of those. I’m sure the league will take a hard look at it. Those are the kinds of impact hits that don’t need to be a part of our game right now. The guy is clearly defensive less and got targeted right in the head. There’s a chance to hit in the strike zone and be somewhere else and not be there like that.”

After catching a pass over the middle in the second quarter, Cooper ducked his head and shoulders as Broncos safety Darian Stewart closed in and delivered a hard head-down blow with his shoulder into the back of Cooper's head and his neck.

Cooper appeared unconscious for a seemingly extended period but eventually walked off the field with assistance.

The Raiders' Derek Carr said a postgame conversation with Cooper left the quarterback feeling relatively positive, though seeing Cooper motionless on the ground was hard, especially since Carr felt some responsibility for the pass and then hit.

“Anytime I throw a ball and I feel like I had anything to do with it, it rips my heart out,” Carr said. “I’m not even going to lie, I had to hold back the motions of him getting hit and thinking it was my fault. The way the linebacker played it, I had to throw it where I had to throw it. But anytime he gets hit, I feel terrible. (Center Rodney Hudson) saw it on my face and said, 'Hey man shake it off, we gotta win this game.' I was like 'You’re right, I’ll be good, but that’s my brother.'”