Get tickets and join the fans at a game at Stade du Moustoir. If there's nothing scheduled while you're in the area, you might like to check if they give a tour of the grounds.
To explore this sporting facility, make tracks to Lorient. You'll find plenty of other interesting attractions in the area, including Golf Blue Green Val Queven, Sous-marin Flore, and Citadelle de Port-Louis.