Buffalo Bills cornerback Vontae Davis retired from the NFL at half-time in his side's 31-20 loss to the Los Angeles Chargers on Sunday.
Davis, 30, started the game but said he "had an honest moment with myself" during it and told the side's coach, Sean McDermott, that he was "done".
He later issued a statement saying he had not intended to show any disrespect to his team-mates or the coaches.
"This was an overwhelming decision but I'm at peace with myself," it read.
Davis, who made his NFL debut 10 years ago, said he knew he could no longer physically compete at the highest level.
"It's more important for me and my family to walk away healthy than to wilfully embrace the warrior mentality and limp away too late," he added.
The Bills trailed 28-6 at half-time when Davis made his decision.
Bills linebacker Lorenzo Alexander said he had found out during the second half of the game.
"I never have seen that. I don't have nothing to say about Vontae," he told ESPN.
"I'm going to give him a little bit more respect than he showed us today, as far as quitting on us in the middle of the game".
Vontae Davis released a statement following the game