The cowards will just stop playing the anthem.
There's a dirty little secret about these big-time sports organizations that may surprise a lot of people: These leagues don't give a sh!t about sports fans.
The whole business of big-time sports has so thoroughly saturated the market that they're increasingly catering to people who aren't even sports fans at all. That's why they've turned their events into entertainment spectacles and pushed the actual sport into the background to the point where it's almost secondary.
Nowhere is this more obvious than in the NFL ... where Super Bowl commercials get more coverage than the game itself, and the lead act for the halftime show is some nitwit pop star who looks like he/she belongs on the cover of National Geographic or in the Mos Eisley cantina scene in the original "Star Wars" movie.