Kealohi, the Constitution does not “presumes how it is that they can choose to use the NFL as their stage despite nonownership.”  The First Amendment prohibits the government from interfering in the free exercise of speech and religion, but it does not prohibit owners of private businesses from establishing rules of conduct for their employees.  NFL owners have a right to require their employees, a.k.a. players, to be on the sideline, helmets in hand, standing at attention, and facing the flag during the playing of the National Anthem.  Many people evoke the First Amendment in a private setting, in the belief they have an absolute right to say what they want and speak what they want, but that is not true in a private work place.