President Trump offered a dire warning for the NFL if it allows its players to kneel during the national anthem.

During a campaign interview with his son Donald Trump Jr., the president was asked about NFL superstar Drew Brees and the apologies he gave following the backlash for saying that kneeling during the anthem is "disrespectful."

Trump reiterated his disappointment in the New Orleans Saints quarterback, saying he was "shocked" that Brees took back his "beautiful statement" regarding the anthem and the American flag.

TRUMP SAYS HE 'ABSOLUTELY' WOULD SUPPORT COLIN KAEPERNICK GETTING SECOND SHOT IN NFL DESPITE KNEELING CONTROVERSY

"I think he hurt himself very badly and I was going to put ou that he'll regret that in the future years because you stand for the flag, Trump said about Brees' reversal. "You have to stand for the flag and the anthem. Our national anthem, you have to stand."

The president then pivoted to remarks made earlier this month by NFL Commissioner Roger Goodell, who earlier this month said the league was "wrong" for not listening to its players and will "encourage all to speak out and peacefully protest."

"I think the NFL's gonna have a lot of problems if they don't and I think the same thing with U.S. Soccer- they said they're not gonna have to stand," Trump told Trump Jr. "And if they don't stand, nobody is gonna want to watch it and I think they're gonna have a lot of problems."

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He continued, "I like Roger Goodell. I was very shocked that he made that statement. It didn't even look like there was any pressure on him, he made it out of nowhere in summertime. What's he doing? Why is he doing that? So I was disappointed with Roger Goodell. I was very disappointed with Drew Brees... He just caved under the pressure."

On Wednesday, Trump said he would "absolutely" support former San Francisco 49ers quarterback Colin Kaepernick getting a second chance in the NFL as long as he still has the skills to play in the league despite the kneeling controversy.