The NFL owners will be meeting next week.  I think I've come up with something that just might appease all concerned.

The first thing the NFL must do is define the purpose of the playing of the National Anthem.  This might be more difficult than it sounds, especially in today's divided society.  In addition, according to a recent exposé, the patriotism shown at NFL games may not be all that genuine (although it is unclear as to whether this practice persists).  However, if they can somehow thread that most delicate of needles, it can be done.  Here is how they can pull that thread:

Declare the following:

"The purpose for the playing of the National Anthem is to remind players, coaches, and fans alike that no matter whom we want to win and who actually does win, this is just a game, and we are all one nation.  We salute one flag; we sing one anthem.  To this purpose, it is incumbent on all players to project this purpose by standing in unity, expressly for the anthem and our flag (if, as the players contend, their kneeling is not about the anthem or the flag).

"If there is a public, peaceful statement any player wishes to make, a designated 30-minute period, immediately following the conclusion of the game, will afford any team personnel the opportunity to express that statement.  Fans who wish to be a part of that can stay, and others may leave at their leisure."

This way, all people and relevant symbols are respected, the anthem and presentation of the flag are segregated to their own acknowledged time slots, and nothing is thrown in anyone's face.  If the fans want to stay, they can.  If they want go, they can feel free without abandoning the game they paid so much to see.
Let's see what the owners actually come up with.