<human>: Alright, for those who are wondering: This is a junior varsity lacrosse team, and we're all sophomores and freshman (I'm a sophomore.)
I just came back from a game of which we should of won 10+ to 0, but instead we barely won in overtime. When we came back to the lockerroom, I was appalled by my guy's behavior: acting like little leaguers who won the biggest tournament in the region. When I threatened extra runs later in the week, one of the more respectful players told me not to be such a child (irony?) I might be at fault there for being a bit of a hard-ass, but dammit I've put up with this shitty attitude for too long. I plan on talking with the coach when I get the chance, but I fear it will not be enough.
Can anyone present me the best course of action when it comes to instilling discipline within this group of about 20 undergrad high schoolers? I am one of three captains, but I'm beggining to believe that it's simply a title and nothing more. Please, I need advice before going in blind and appearing like a douche.

Summarize the given text in a few sentences.
<bot>: a Highschool jv laX team is in need of serious discipline, how can a team captain turn these boys's attitude around?