Is this a story for me ...

As JFS said, this doesn't seem that complicated.
You must get a police report and arrest record for the kid. But if he was arrested, he was arrested and it should be on paper somewhere, minor or not (think police report, jail records, bail hearing/courthouse, etc). Do they really redact the name of every minor in the jail log? If you can't get that, no story. But once you've got a DUI arrest confirmed, you're all set. "Star pitcher arrested for DUI, but look, he's still pitching."

Go ask the coach and the school and the family and the team that drafted him, and, odds are, they'll tell you to go fuck yourself. That's fine, all in the game. You probably won't get the "parents pressured school to let him play" angle; you might get "kicked out of school," which is secondary but certainly bolsters your case. But if you can prove that he was indeed arrested and charged w/DUI, you're not going to get in any trouble for reporting that. And if he's still pitching it's a damn good story. Good luck.