If they refuse to play, they'll get docked all sorts of points. Pointless stands won't really accomplish much. And frankly, all the teams need to clean house when it comes to their terrible fans...because you KNOW that if we had fans there, there would be a fight. In fact, I bet there still will be, outside the stadium.
Should just have the final be made up of women and children though. Would be a great look if Athenians attacked busloads full of children.