The fury unleashed on Drew Brees came fast. The New Orleans Saints quarterback said in an interview Wednesday that he would never agree with N.F.L. players who knelt during the national anthem to protest police brutality, and he was immediately condemned.

A host of players, including some of his teammates, responded with statements of their own, calling Brees’s comments hurtful and criticizing him for ignorance of or callousness to the struggles of African-Americans.

“Drew Brees, you don’t understand how hurtful, how insensitive your comments are,” Malcolm Jenkins, Brees’s teammate, said in a video posted to Twitter. “I’m disappointed, I’m hurt, because while the world tells you, ‘You are not worthy,’ that your life doesn’t matter, the last place you want to hear it from are the guys you go to war with and that you consider to be your allies and your friends.

“Even though we are teammates, I can’t let this slide.”

The backlash to Brees comes during a week in which a range of players have been speaking out on the killing of George Floyd in police custody in Minneapolis and racial injustice.

On Thursday night, players posted a montage of some of the league’s biggest stars — including Chiefs quarterback Patrick Mahomes and Cowboys running back Ezekiel Elliott — calling on the N.F.L. to condemn racism and admit that silencing players from peacefully protesting is wrong, an apparent reference to the Colin Kaepernick affair. (The N.F.L. said on Instagram on Thursday that it stands “with the black community because Black Lives Matter.”)

But the backlash Brees received was notable not just because it targeted one of the league’s premier players, but because it broke an unwritten rule that teammates vent their personal differences in private, extolling the primacy of the team in public.

Brees had made similar remarks in 2016, when he criticized Kaepernick for initially protesting social and racial injustice by sitting during the national anthem.

Four years ago, a small group of players openly supported Kaepernick and joined his protest, after much deliberation over his method and message. Now, the ferocity of the reaction to Brees’s comments is a sign of how what was once a third rail issue in the league — acknowledging racially driven violence and systemic racism — has become a necessary conversation to be supported, if not outright embraced, not just by African-American players, but also by white players, coaches and owners.

Unlike in 2016, when the league struggled to address the wave of police shootings headlined that year by that of Philando Castile, the video of George Floyd’s killing while in police custody has occurred at a time when the N.F.L. is more proactive about addressing the issue.

On Saturday, the league and many team owners, including those who previously said little or opposed Kaepernick’s protest, issued statements. For their part, players, like much of the country, have been outspoken in condemning the status quo, and have done so without public retribution — a rarity in a league where the norm is to avoid any commentary that might draw uncomfortable headlines.

“The existence of the protests worldwide and in all 50 states has provided cover for the players to say things, and they have taken advantage of that cover,” said Jay Coakley, a sociologist and author of the textbook, “Sports in Society: Issues and Controversies.”

The act of kneeling in protest during the anthem is still subject to laissez-faire oversight, as it is still not technically allowed by league policy. In May 2018, the N.F.L. owners said that players could no longer kneel during the national anthem without being subject to punishment or their teams facing possible financial penalties. Players could, however, stay in the locker room during the pregame ceremony, when the anthem is played.

But after the N.F.L. Players Association filed a grievance challenging the decision, the league never enforced the policy. Last year, several players, including Eric Reid and Kenny Stills, continued to kneel during the playing of the anthem and were not penalized by the league.

On Thursday, Brees walked back his position in a post on Instagram, saying his earlier comments were “insensitive and completely missed the mark.” Brees also asked for forgiveness and said that he took full responsibility for his words.

“I recognize that I should do less talking and more listening … and when the black community is talking about their pain, we all need to listen,” he wrote.

A few players praised Brees for his apology, including Demario Davis, a Saints linebacker. Brees’s apology “is a form of true leadership and I would say it because that’s taking ownership,” Davis said on CNN. “It’s not easy to come out and admit when you’re wrong.”

Brees’s offensive teammate, Alvin Kamara, a Saints running back, also seemed to welcome the apology. “We talked and I explained to him where he dropped the ball and he understood,” Kamara wrote on Twitter. “But now it’s time for us to be part of the solution, not the problem.”

Many others may not be so quick to forgive or forget.

Trayvon Mullen Jr., a cornerback for the Las Vegas Raiders, wrote on Twitter, “September 21,” the date his team is scheduled to play Brees’s Saints.

Some players have pointed back to 2016 as a means of calling out players who have been sanctimonious in their criticism of Brees. After Aaron Rodgers, the Green Bay Packers quarterback, seemed to take aim at Brees’s in an Instagram post on Wednesday, Martellus Bennett, Rodgers’s former teammate, said that many white players were silent a few years ago when Kaepernick opened the discussion on police brutality. Bennett was one of the players to take a knee, protesting during the 2017 season he spent in Green Bay. Rodgers linked arms with his teammates, but did not kneel.

“I don’t want to see y’all paint these dudes as white saviors that were always speaking up,” he said on Twitter. “It’s just not true. I was there.”

Still, the debate in all corners of the N.F.L. shows a change in culture over the past four years. It is unclear how many players and coaches will take concrete steps to address social injustice, but they appear more willing to acknowledge it or express their support of change in public statements. That could change once they return to training camp and have to face television cameras and potentially fans, some of whom are bound to disagree with them.

But for now, the dialogue appears to be subsuming the league. The Detroit Lions on Monday decided not to talk about football, instead holding a team-wide discussion between players and coaches about the killing of Floyd in Minneapolis.

On Thursday, the Packers released a two-minute video that begins with the title, “Enough is Enough.” It is followed by players calling for steps to address social injustice against African-Americans and players saying “It is time for change.”

Troy Vincent, the N.F.L.’s executive vice president of football operations, wrote an op-ed for The Athletic that he reposted in a series of tweets about speaking to his son Taron. Both Vincent and his son are African-American, and the writing details a conversation about how Taron should respond if he were to be stopped by police as he drove back to the Ohio State campus.

But even in his lofty position, Vincent said that he had been challenged by his daughter Desiré to speak publicly.

“As an institution, the N.F.L. has the ability to bring people to the table,” he said. “We can be bridge-builders and facilitate discussion. We can drive awareness around issues. It doesn’t matter what the issue is, our platform allows us to do that.”