Football fans left confused after Bears star appears to walk off the field in the middle of a play

Football fans were left confused after a play in the game between the Arizona Cardinals and the Chicago Bears - where one player appeared to leave the field while the ball was still live.

Early in the first quarter of the game, Chicago Bears wide receiver DJ Moore was seen walking off the field (top right in the video below) as his quarterback - Caleb Williams - scrambled to try and find a pass.

The play continued for about ten more seconds before Williams fired an incomplete pass on the opposite side of the field.

Bears fans were left stunned, with one in particular - Barstool Sports' Dan 'Big Cat' Katz - furiously tweeting.

'What the hell is DJ Moore doing here? He just walks off the field mid play?!?,' Katz tweeted.

Former defensive end and current NFL analyst JJ Watt replied to Katz to try and calm him down, saying, 'Looks to be limping and goes straight to the bench. So probably felt a tweak. Or, he realized he stepped out of bounds and thus was no longer an eligible receiver, so to eliminate any potential confusion for Caleb, he stayed off the field.'

Katz replied: 'Totally get the illegal touching thing, but it looked like he tight roped the sideline then almost willingly stepped out. Are guys taught to stay out of bounds if they accidentally step out of bounds to avoid illegal touching?'

Watt replied again: 'Judging solely off this video, my guess (completely a guess, only based on what I'm looking at) would be that he felt a tweak or something. That little hop right at the sideline followed by a limp and going straight to the bench to sit down, all lines up with feeling a tweak.'

He continued, saying, 'For the illegal touching point (which I don't think is the reason in this case, the more I watch it), you can look at [New England Patriots tight end] Hunter Henry on the crazy [Patriots quarterback] Drake Maye touchdown from yesterday as an example. He stepped out the back of the end zone, so then he stayed out and backed up to basically let Drake know he wasn't an option.'

For some fans, it mirrored an incident involving Indianapolis Colts quarterback Anthony Richardson - who walked off the field because he was tired during a game against the division rival Houston Texans.

Moore did return to the game and finished with four catches for 33 yards in the Bears' 29-9 loss to the Cardinals.

He has not been placed on any injured list after the game finished.