Oakland Raiders wide receiver Amari Cooper took a massive hit to the head early in the second quarter and didn’t return to Sunday’s game, a 27-3 defeat to the Seattle Seahawks in London.

Cooper had cut across the middle of the field and attempted to catch a short pass. While reaching down low for the ball, Seahawks safety Bradley McDougald drilled him hard in the head and shoulder, sending the 24-year-old to the ground.

Cooper stayed on the ground for several minutes before he was helped up and taken to the locker room. He was diagnosed with a concussion and didn’t return.

While it initially looked like it could have been ruled a penalty for helmet-to-helmet contact, no flag was thrown.

Raiders head coach Jon Gruden said after the game that he thought the hit was helmet to helmet and was concerned for his health.

“The big thing right now is I hope Amari is OK,” Gruden told reporters. “Losing Amari the way we did, I just hope he’s OK.”

Fox Sports rules analyst Dean Blandino tweeted out shortly after the hit that a flag should have been thrown on the play, as it “appeared to be forcible contact to the head and neck area” on a defenseless player.

It was reported on Sunday morning that the Raiders are shopping both Cooper, their 2014 first-round NFL draft pick, and 2015 first-rounder Karl Joseph.

Cooper has 22 receptions for 280 yards and one touchdown so far this season. He did not have a reception prior to leaving the game on Sunday.

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