Amari Cooper ruled out with a concussion after a hit to the head vs. Broncos

The wide receiver was knocked out at first, but was able to walk off the field under his own power.

Amari Cooper left Broncos vs. Raiders in the second quarter after taking a brutal hit from safety Darian Stewart. Cooper was initially knocked unconscious.

The team confirmed that Cooper has a concussion and will be out for the rest of the game.

Medical staff brought out the cart for Cooper, but he was able to get up and walk off the field under his own power.

Stewart was flagged for unnecessary roughness. But it wasn’t a helmet-to-helmet hit. It looks more like incidental contact.

Stewart was also hurt on the play. He ran off the field after the hit with what appeared to be a shoulder injury or possibly a stinger, according to ESPN’s Jeff Legwold. But he was able to return to the game quickly.

Cooper’s injury takes yet another receiving target away from Derek Carr. The Raiders also lost Michael Crabtree when he was ejected after a fight between him and Broncos cornerback Aqib Talib that set off a full-fledged brawl between the two teams.

Before the injury, Cooper had one reception, which was a 9-yard touchdown. The Raiders lead the Broncos 14-0 at home.