LOUISVILLE, Kentucky (CBS SF & AP) — President Donald Trump has taken a swipe at controversial NFL quarterback Colin Kaepernick at a campaign-style rally in Louisville, Kentucky.

Kaepernick, who played for the San Francisco 49ers but now is a free agent, hasn’t yet been signed to another team.

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Trump told the crowd he read an article reporting that NFL owners don’t want to pick Kaepernick up “because they don’t want to get a nasty tweet from Donald Trump.”

“Do you believe that?” he asked the enthusiastic crowd.

Kaepernick refused to stand during the national anthem at the start of NFL games last season to protest police treatment of minorities.

Trump says of the people of Kentucky, “They like it when people actually stand for the American flag.”

Kaepernick’s free agency woes have been the source of discussion since director Spike Lee put on an Instagram post on Sunday calling the lack of interest in the veteran as being ‘fishy.’

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On Tuesday, Lee went even further with a post questioning whether there was collusion among the NFL owners to punish Kaepernick’s Anthem protest.

Lee has been advocating for his hometown team — the New York Jets — to sign Kaepernick.

“The New York J-E-T-S Need A Quarterback,” wrote Lee on Instagram, who said he spoke with Kaepernick over a weekend brunch. “Who Is The J-E-T-S Quarterback? Is My Man Joe Willie Namath Coming Back? Crazy Times We Live In.”

Meanwhile, his former head coach Jim Harbaugh also joined in the discussion Tuesday, telling Pro Football Talk that Kaepernick can still be a difference maker for a team.

“I’ll tell you the same thing I tell them: I think he’s an outstanding player and I think he’s a great competitor who has proven it in games and has the ability to be not only an NFL starter but a great NFL player,” said Harbaugh, the former San Francisco 49ers head coach who now runs the football program at the University of Michigan.

“He’ll have a great career and be a great quarterback, win championships,” Harbaugh added.

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