Travel Team, Mike Lupica
Sports Fiction. Travel Team is such a great book that I'm on my 5th time reading (not kidding).
Its about a small twelve year old boy who doesn't make his travel team, so he starts his own, made out of other kids that didn't make the cut. Throughout the book, you follow Danny's (the main character's) team as they overcome challenges and eventually emerges as world champions(for the 7th grade). 11+ for language and references to drinking.