Concussion experts blasts 'insane' Josh Allen return in Bills loss after he stayed down when his head bounced sickeningly up off the turf

Concussion campaigners have slammed the decision to allow Josh Allen to return to the field minutes after the Bills quarterback suffered a sickening blow to the head against the Texans.

Allen's head bounced off the turf after a tackle during Buffalo's 23-20 defeat by Houston on Sunday. The quarterback was left face down, his left wrist bent into the turf, following the brutal hit to his head.

Concerned teammates stood over Allen before he headed to the medical tent for evaluation, only to return to the game shortly.

It comes only weeks after Dolphins QB Tua Tagovailoa suffered another concussion and Chris Nowinski - a neuroscientist and founding CEO of the Concussion Legacy Foundation - slammed the 'insane' and 'risky' decision.

'It's insane that Josh Allen was put back in after this hit. Even if he says he's fine, why bet the franchise QB that concussion symptoms aren't delayed?' he wrote on social media. 

'Protocol aside, how are we taking risks like this just a few weeks after another Tua concussion?'

Nowinski added: 'Fact: All #concussion protocols are imperfect. If I saw a player's head bounce 18 inches off the turn and his left wrist fold like Allen's did here, I'd call it "no protective action when falling", a concussion sign. I'd at least sit him for the game. Why are we not cautious?'

Earlier on Sunday, Tommy Tremble of the Panthers appeared to be knocked unconscious after taking a blow to the head. 

Another clip from the Bills-Texas game, meanwhile, appeared to show Allen being handed something by a member of the bench before he returned to the field. Sports doctor Jesse Morse claimed it was smelling salts and he called for a 'huge penalty' over the decision to let Allen play on.

'Josh Allen appears to have SUFFERED A CONCUSSION, they gave him SMELLING SALTS then allowed him to return to the game,' he said. 

'This should be a HUGE PENALTY and VERY risky for Josh Allen’s health. He could have suffered another concussion which could have caused second impact syndrome, which can be deadly.'

After trainers rushed on to the field, Allen reportedly stayed down for around 20 seconds before he sat up and made his way off.

Following CJ Stroud's dramatic fumble, however, Allen reportedly attempted to run out of the tent, only to be pulled back in.

Mitch Trubisky briefly replaced him under center but soon Allen put his helmet on and ran back on. He was unable to prevent the Bills from suffering an 23-20 loss.