He wrote that such incidents were “the exact reason why guys are kneeling during anthem.”
“Me flicking the person off is more deserving,” he wrote. “I do apologize to my teammates and the organization. But at some point you keep calling us the N-word, we going to start acting up.”
Race has been a major issue for the N.F.L. this year, with many players kneeling during the national anthem to protest racial discrimination and police brutality. President Trump has weighed in, scolding those who do not stand.
Pryor stood for Monday’s anthem — “I chose not to kneel because as a team we decided to be one and stand,” he wrote — but at least two Chiefs players did not. The Chiefs won the game, 29-20.
Pryor, 28, was a quarterback at Ohio State and initially in the N.F.L. with the Raiders, then converted to wide receiver with the Browns. He was briefly a member of the Chiefs, but he did not get in a game.
In May, Orioles outfielder Adam Jones was racially taunted by some fans in Boston. He received an extended ovation from Red Sox fans the next night.