CNN reported over the weekend that Trump threatened NFL players telling them that they need to find another way to protest or lose pay:
https://detroit.cbslocal.com/2018/08/10/president-trump-to-players-find-another-way-to-protest/
https://detroit.cbslocal.com/2018/08/10/president-trump-to-players-find-another-way-to-protest/
In another tweet, Trump also reiterated his belief that players, who don't stand for the National Anthem should be penalized.
He wrote, "Be happy, be cool! A football game, that fans are paying soooo much money to watch and enjoy, is no place to protest. Most of that money goes to the players anyway. Find another way to protest. Stand proudly for your National Anthem or be Suspended Without Pay!"