He played in Major League Baseball (MLB) from 1924 to 1938 for the St. Louis Cardinals, Philadelphia Phillies, Pittsburgh Pirates, Cincinnati Reds, and Boston Bees.

[1][2] Thevenow was acquired by the Cardinals on September 3, 1924, when he was purchased from the Syracuse Stars of the Class AA International League, where he played 140 games that season.

[3][4] During the 1926 season, Thevenow hit the first home run of his major league career on September 17 off Cincinnati Reds pitcher Jack Knight, an inside-the-park homer that was part of 10–1 win over fading Cincinnati; the Reds went on to lose seven of their last nine games down the stretch.

Five days later, Thevenow would hit another inside-the-park home run, the second and final regular season home run of his career, as the Cardinals beat the Brooklyn Dodgers by a score of 15–7, putting the Cardinals 2+1⁄2 games ahead of the Reds for first place in the National League.

Thevenow would go on to get 10 hits in 24 at-bats for a .417 batting average, leading the Cardinals to win the series in seven games.