Evidently you don’t know??? How can you comment if you don’t even know what it is about?
It is more appropriate for me to ask you why you are commenting when you don't know what it's about.
Have you ever read the First Amendment? Here it is (emphasis added):
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
That's the whole thing. The First Amendment, as the text makes clear, is a restriction on government power. It has no applicability whatsoever in private enterprise. There is no right of free speech in connection with private employment. The NFL is free to sanction any of these jerks and the teams are free to fire any of them. There is no Constitutional issue involved at all. This is Constitutional Law 101.