I'm going to be the lone voice of dissent...but I would go with the jean mini. Better for going out after the game, and casual enough that it works for the game as well. Plus I like being a little feminine when I go to sporting events.
I agree with gingembre1. Since you're going to a game and bar hopping as well, I would wear the mini as well. It's still casual but shows that you're still a girly girl.
I think the way to avoid looking all girly-girl is to make sure you are wearing flat sandals like nice beaded flip flops and a sporty tank. For example:
while the outfit seashells posted is super cute and almost swayed my thinking, i vote capris. i wore a skirt to a baseball game once and it was so blasted hot i was uncomfortable sitting like a "lady" all night. my legs were sweaty and sticking together. not good. perhaps where you are is not as hot as it is here in atlanta and that wouldn't be a problem for you.