 Born in Hamtramck, Michigan, Gromek originally began playing professionally with the Indians organization as an infielder, but became a pitcher early on, and made his major league debut in 1941.He played sparingly his first three years before becoming an everyday starter in 1944 and 1945, earning his lone All-Star appearance in the latter year.After the war ended, he became a spot starter, spending time as both a starting pitcher and relief pitcher.