Zuber made his professional debut in 1932, and joined the Zanesville Greys of the Middle Atlantic League, a minor league team in the Indians' organization, in 1933. After several more seasons in the minor leagues, Zuber spent most of the 1936 season playing for the Greys, finishing with a 17–8 record and over 200 strikeouts. He made his Major League debut on September 16, 1936 with the Cleveland Indians. In his first game against the Boston Red Sox, he pitched five innings and earned a win in the six-inning affair which was shortened due to rain. After starting a second game and finishing the season with one win and one loss, he spent the 1937 season playing for the Milwaukee Brewers of the American Association. He rejoined the Indians during the 1938 and 1939 seasons, and was used as a relief pitcher. In the two seasons, he posted a 2–3 record and finished 16 games. He finished the 1940 season with a 1–1 record, and on April 21, 1941, the Washington Senators purchased his contract from the Indians.
Senators and Yankees
Zuber spent two seasons with the Senators, starting seven games and finishing 19 both seasons. He was classified 4-F by the military, and as a result was able to remain with the team during World War II. In 1942, he won a career high nine games. On January 29, 1943, Zuber was traded to the Yankees with cash for Jerry Priddy and Milo Candini. The 1943 New York Yankees went on to win the world series, with Zuber finishing the season with an 8–4 record over 20 games, which included 13 starts and 7 complete games. He did not pitch in the 1943 World Series. He remained an occasional starter the following two seasons, winning five games in both seasons and earning a 3.19 earned run average in 1945. Although he only posted a 5–11 record for the season, the Yankees were shutout 14 times during the season, seven when Zuber was pitching, a club record.
Boston Red Sox
At the start of the 1946 New York Yankees season, Zuber pitched three games and had an ERA of over 12 before he was purchased by the Boston Red Sox on June 18. He went on to post a 5–1 record and a career-low 2.54 ERA during the remainder of the season. On September 21, Zuber won a game against the Senators, which gave the Red Sox their 100th victory of the season. Zuber appeared in game four of the 1946 World Series, pitching two innings and allowing one run in a 12–3 loss to the St. Louis Cardinals. After pitching 20 games during the 1947 season, Zuber returned to the minor leagues for a season, pitching for the Louisville Colonels in 1948, before retiring.
