第二次世界大战欧洲战场
Heintzelman lost three seasons (1943–45) in the prime of his career, serving in the United States Army in the 65th Reconnaissance Troop (Mechanized) of the 65th Infantry Division in the European theatre of World War II. He returned to the Pirates' pitching staff in 1946 and the following May his contract was sold to the Phillies.