Ostermueller began playing pro ball with his hometown club in Quincy, IL. Elbow surgery saved his career early on. As a Red Sox rookie, he walked 12 Senators in a July 30, 1934 game. He three times recorded 13 wins, the last time with Pittsburgh in 1946, and pitched for the Pirates until age forty-one. Considered a good-hitting pitcher, he batted .234 lifetime.