Players can do whatever they want ON THEIR OWN TIME.
Apparently he doesn't understand that the ticket paying fans in the stands and those watching on TV have the same right to leave and not come back.
Trump is telling Goodall he should be backing the fans and not a few disruptive rebel-rousers. He's telling him he should be supporting respect for the flag and national anthem of our country and not some showboating player protesters.
In the end, Goodall will rue the day he decided to push back at Trump and the NFL fan base and instead backed a few disgruntled players.