Steinbrunner left his professional football career in 1954 after only eight regular season games to fulfill his military requirement. With a lingering knee injury from his collegiate days and the Browns winning consecutive NFL titles in 1954 and 1955, he later opted to stay in the service. He joined the U.S. Air Force, first in the air police and later as a navigator, and in between was an assistant football coach for four seasons at the U.S. Air Force Academy in Colorado Springs.