His pro career began at the age of 18 after he graduated from
Birdsboro High School, when he was signed by the Philadelphia Athletics' legendary manager,
Connie Mack, in 1936. But Gumpert had been throwing
batting practice for the Athletics at
Shibe Park as far back as 1934, while he was still in school. He spent his entire
rookie 1936 season with Philadelphia, getting into 22 games with three
starting pitcher assignments, and threw two
complete games, including a two-
hit, 5–2 triumph over the Chicago White Sox on August 27. It was Gumpert's first
MLB victory, and the two
runs he surrendered were both
unearned. Gumpert spent most of 1937 and 1938 in the
minor leagues, getting into only 14 games for the Athletics. In July 1939, still in the minors, he was acquired by the New York Yankees' organization. In 1946, he was able to make the Yankees' major league roster. In his first season with the Bombers, earning an 11–3
won–lost record with a
earned run average of 2.31 in 33 games, including 12 starts, and 132
innings pitched. Over his ten-season career, which spanned 17 years, Gumpert won 51 games, lost 59, and compiled a 4.17 earned run average. Of his 261 games pitched, 113 were starts and 148 came out of the
bullpen, and he was credited with 47 complete games, six shutouts and seven
saves. He allowed 1,099 hits and 346
bases on balls, with 352
strikeouts, in 1,052 innings pitched. Gumpert then played three more seasons, 1953–1955, at the highest levels of minor league baseball before hanging up his glove. ==Manager, coach and scout==