Why even have the anthem at a game in the first place? We don't in the UK.
I’ve never understood it. Do people forget what country they’re in?
I'd be quite happy with no anthem at sporting events, and no Pledge of Allegiance in schools either. Mass displays of patriotism are the hallmark of an authoritarian country, not a free one. Loyalty and patriotism can't be imposed from outside (and social/peer pressure is a form of imposition). They have to be earned by the state, and come from a person's convictions.