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

Early in the first quarter of the game, Chicago Bears wide receiver DJ Moore was seen leaving the field (top right in the video below) while his quarterback – Caleb Williams – struggled to find a pass.

There were about ten seconds left in the play before Williams fired an incomplete pass to the opposite side of the field.

Bears fans were stunned, with one in particular — Dan “Big Cat” Katz of Barstool Sports — tweeting angrily.

“What the hell is DJ Moore doing here?” “He just walks off the field in the middle of the game?!?” Katz tweeted.

Bears receiver DJ Moore (circled) was seen leaving the field in the middle of a game on Sunday

Former defensive end and current NFL analyst JJ Watt responded to Katz to reassure him by saying, “Looks like he's limping and going straight to the bench.” So that probably felt like a pinch. Or he realized that he had left the field and was therefore no longer a suitable receiver. To eliminate any possible confusion for Caleb, he remained off the field.”

Katz replied: “I completely understand the illegal touching thing, but it looked like he strapped himself to the sideline and then almost voluntarily got off.” Are boys taught to stay off the field if they accidentally do that Leave the field to avoid illegal contact?”

Watt responded again: “Judging from this video alone, I would guess (totally a guess, just based on what I'm looking at) that he felt a pinch or something.” That little bounce right on the sideline, followed by a limp and going straight to the bench to sit down, all consistent with the sensation of a pinch.”

He continued, saying, “For the illegal touch point (which I don't think is the reason in this case the more I look at it), you can watch (New England Patriots tight end) Hunter Henry about the crazy ( Patriots) look at quarterback) Drake Maye's touchdown from yesterday as an example. He stepped out behind the end zone, so he stayed out and went back, basically letting Drake know he wasn't an option.”

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

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

He was not placed on the injured list after the end of the game.