He was traded after the 1937 season to the Cincinnati Reds, where he found a place on the major league roster as a backup behind Ernie Lombardi.

His family moved to Fullerton, California, when his father, Claude, got a job working in the city's oil fields.

Hershberger attended Fullerton Union High School, where he distinguished himself on both the baseball and football teams, playing alongside Arky Vaughan and future President Richard Nixon.

"[3] In 1930, scouts Bill Essick of the New York Yankees and Art Griggs of the Pittsburgh Pirates came to Fullerton to watch Vaughan and Hershberger play, respectively.

As a result, Yankees owner Jacob Ruppert noted that he would spend the offseason working to get the players on major league rosters.

[9] On December 3, 1937, Hershberger was traded to the Cincinnati Reds for shortstop Eddie Miller and $40,000, ending his tenure in the Yankees organization.

[10] Reds manager Bill McKechnie noted that Hershberger was playing so well in spring training that there was the possibility of him beating out Ernie Lombardi for the starting catcher job in 1938.

Lombardi then sprained his ankle on July 26, putting Hershberger in the starting role indefinitely; at the time his batting average was .354.

[15][16] However, in a game against the New York Giants at the Polo Grounds on July 31, the Reds took a 4–1 lead into the ninth and lost 5–4, with the comeback capped by a game-ending home run by Harry Danning.

[16] Hershberger blamed himself for the losses to the Giants and Bees, telling third baseman Billy Werber that "If Ernie had been catching, we wouldn't have lost those ball games.

[3][16] After he missed the first game of another doubleheader against the Bees, McKechnie had Dan Cohen, a friend of Hershberger's, head to the hotel to check in on him.

[3] After the second game, McKechnie had coach Hank Gowdy bring all the players together in the locker room, stating, "I want to tell you something.

[1] The Cincinnati Reds would go on to defeat the American League champion Detroit Tigers in seven games to win the 1940 World Series.