President Trump called on NFL owners to fire players who kneel during the national anthem, during a rambling speech in Alabama Sept. 22. (Victoria Walker/The Washington Post)

President Trump appeared at a campaign rally in Huntsville, Ala., on Friday night, ostensibly to support the senatorial bid of fellow Republican Luther Strange. But the speech veered off topic, and eventually landing on a few points regarding the NFL and sparking response from the NFL and its players’ union.

Without mentioning him by name, Trump made reference to Colin Kaepernick and the protests against injustice toward African Americans the former San Francisco 49ers quarterback led last NFL season by taking a knee during the national anthem.

“Wouldn’t you love to see one of these NFL owners,” wondered the president, “when somebody disrespects our flag, to say, ‘Get that son of a bitch off the field right now, out. He’s fired. He’s fired!’ ” The hypothetical was met with cheers from the assembled crowd.

Trump also said such an owner would “be the most popular person in this country. Because that’s a total disrespect of our heritage. That’s a total disrespect for everything we stand for.” He added that if fans were to “leave the stadium” in response to a protest, “I guarantee things will stop.”

DeMaurice Smith, the executive director of the NFL Players Association, responded on Twitter early Saturday morning that the union “will never back down.” He also challenged NFL Commissioner Roger Goodell to respond to Trump’s comments:

Goodell issued a statement later Saturday morning that read: “The NFL and our players are at our best when we help create a sense of unity in our country and our culture. There is no better example than the amazing response from our clubs and players to the terrible natural disasters we’ve experienced over the last month. Divisive comments like these demonstrate an unfortunate lack of respect for the NFL, our great game and all of our players, and a failure to understand the overwhelming force for good our clubs and players represent in our communities.”

Trump had more to say on the subject of players kneeling during the anthem on Saturday via Twitter, including a response pointed directly at Goodell.

Trump also discussed at Friday’s rally the league’s television ratings, saying they are down “massively,” and partially claiming credit for the drop.

“Now the No. 1 reason happens to be, they like watching what’s happening with yours truly,” he said. He also added that the amount of big hits called as penalties are a factor as well.

“Today, if you hit too hard, 15 yards, throw him out of the game,” he said while mimicking the act of an official throwing a penalty flag. “They’re ruining the game, right? They’re ruining the game. It’s hurting the game.”

President Trump's demand that NFL owners fire players who kneel during the national anthem set off protests by NFL players, coaches and owners. This is not the first time athletes have used their platform to protest. (Taylor Turner,Amber Ferguson/The Washington Post)

Trump’s comments on how the game is being ruined by an attempt to cut down on big hits came a day after former New England Patriots tight end Aaron Hernandez was diagnosed posthumously with the second-most-severe form of chronic traumatic encephalopathy (CTE). Hernandez committed suicide in April while serving a life sentence for murder.

In addition to Smith’s comments on Twitter, he released a written statement on Saturday morning.

“The peaceful demonstrations by some of our players have generated a wide array of responses,” Smith said. “Those opinions are protected speech and a freedom that has been paid for by the sacrifice of men and women throughout history. This expression of speech has generated thoughtful discussions in our locker rooms and in board rooms. However, the line that marks the balance between the rights of every citizen in our great country gets crossed when someone is told to just ‘shut up and play.’

“NFL players do incredible things to contribute to their communities. NFL players are a part of a legacy of athletes in all sports who throughout history chose to be informed about the issues that impact them and their communities. They chose — and still choose today — to do something about those issues rather than comfortably living in the bubble of sports. Their decision is no different from the one made by countless others who refused to let ‘what they do’ define or restrict ‘who they are’ as Americans.

“No man or woman should ever have to choose a job that forces them to surrender their rights. No worker nor any athlete, professional or not, should be forced to become less than human when it comes to protecting their basic health and safety. We understand that our job as a Union is not to win a popularity contest and it comes with a duty to protect the rights of our members. For that we make no apologies and never will.”

Trump’s remarks regarding national anthem protests also spurred a reaction on social media, from both players and observers.

Trump attempted to buy the Buffalo Bills in 2014, but his bid wasn’t accepted by the league.

Read more:

It’s starting to look like Colin Kaepernick won’t play in the NFL again. What happens next?

From taking a seat to taking a stand: How the NFL has talked about Colin Kaepernick

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Cris Carter gets emotional while discussing CTE, his career and Aaron Hernandez’s diagnosis

Donald Trump: NFL ‘football has become soft like our country has become soft’