NFL Commissioner Roger Goodell on Saturday responded to President Trump's Friday night monologue attacking the NFL and players who kneel in protest during the national anthem, saying the president's "divisive comments" reveal an "unfortunate lack of respect" for the NFL and contributions players make to their communities.

Goodell issued the statement after Mr. Trump spent a portion of his 83-minute speech at a rally for U.S. Senate candidate Luther Strange on Friday night bashing the NFL for allowing games to be less violent, and urging them to fire players like Colin Kaepernick who refuse to stand for the national anthem.

"The NFL and our players are at our best when we help create a sense of unity in our country and our culture," Goodell said in a statement. "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."

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Mr. Trump took to Twitter on Saturday night to criticize Goodell's statement. "Roger Goodell of NFL just put out a statement trying to justify the total disrespect certain players show to our country. Tell them to stand!"

Roger Goodell of NFL just put out a statement trying to justify the total disrespect certain players show to our country.Tell them to stand! — Donald J. Trump (@realDonaldTrump) September 23, 2017

The NFL Players Association, a union for NFL players, responded that they "no longer can afford to stick to sports."

"We will never back down," executive director DeMaurice Smith said in a statement. "We no longer can afford to stick to sports."

Smith said the union "will never back down when it comes to the constitutional rights" of their players and their safety in a "game that exposes them to great risks."

NFL players also took to Twitter Friday night to respond to the president's tirade against the NFL.

Seattle Seahawks cornerback Richard Sherman condemned Mr. Trump's comments on Twitter: "The behavior of the President is unacceptable and needs to be addressed. If you do not Condemn this divisive Rhetoric you are Condoning it!"

The behavior of the President is unacceptable and needs to be addressed. If you do not Condemn this divisive Rhetoric you are Condoning it!! — Richard Sherman (@RSherman_25) September 23, 2017

Cincinnati Bengals safety George Iloka tweeted he "can't take anything our celebrity in chief says seriously."

I can’t take anything our Celebrity in Chief says seriously. He’s a real life clown/troll 🤡 — George Iloka (@George_iloka) September 23, 2017

"Trump stay in your place ... Football have nothing to do with u smh," Washington Redskins linebacker Zach Brown tweeted.

Mr. Trump said disrespecting the flag merits firing.

"Wouldn't you love to see one of these NFL owners, when somebody disrespects our flag, to say, 'Get that son of a b---- off the field right now. Out. He's fired. He's fired!" he said.

But he also lamented that the NFL is ruining the sport by preventing violence with penalties.

"They're ruining the game. They're ruining the game. That's what they want to do," he added. "They want to hit. They want to hit! It is hurting the game."