Buy tickets and join the crowds at a game at Meinau Stadium. If there's nothing on while you're in town, you might like to check if they give a guided tour of the facilities.
Wondering where to find Meinau Stadium? It's in Plaine des Bouchers, and an entry fee applies. If time's on your side, stop by Strasbourg Cathedral, Rohan Palace and Covered Bridge as well. They won't take long to get to from the sporting facility.