Cal Ripken Rules
 

Anyone familiar with this organization and rules?

If so, a team starts a game with 9 players and an injury forces one player out of the game.

What happens?

I believe Cal Ripken (and Babe Ruth) uses OBR as the basis for its rules. So for your scenario, a forfeit would be the call. That said, there may be some stipulation to call the game and let the powers-that-be decide the outcome.

If you're talking about a game that just happened, I'm guessing this was a tournament game. In that case, I can't imagine how the game wouldn't result in a forfeit.