My solution would have been to let the players kneel during the anthem, and then announce after it was over which players knelt. Who would want to buy a jersey of a player who disrespected the flag and anthem. After a while, further action might include having the kneelers kneel at the tunnel entrance, and surely not with the other players. if all the players knelt, so be it.
“Who would want to buy a jersey of a player who disrespected the flag and anthem.”(?)
Blacks and Wiggers.