He was referring to a controversial string of protests started by player Colin Kaepernick last year when he sat or kneeled during the anthem to highlight the treatment of black Americans.
“Wouldn’t you love to see one of these NFL owners, when somebody disrespects our flag, to say, ‘Get that son of a bitch off the field right now… he is fired,” he told a cheering crowd.
NFL commissioner Roger Goodell released a statement saying “divisive comments like these demonstrate an unfortunate lack of respect”.
President Trump, however, doubled down on his comments in a tweet.
The NFL Players’ Association said the president had crossed a line by effectively telling players to just “shut up and play”.
Association president Eric Winston said Mr Trump’s comments were “a slap in the face to the civil rights heroes of the past and present”.
Who else has joined in the criticism?
On Saturday night, the Oakland Athletics’ Bruce Maxwell became the first Major League Baseball player to kneel in protest during the national anthem, mimicking the gesture of protest started by Colin Kaepernick.
His father is in the military and he was born on an army base, US media report. He told a reporter he was “kneeling for people that don’t have a voice”.
