[citation needed] In 1900, while working as a messenger boy, he was sent to the ballpark of the Chicago White Stockings; when their shortstop, Frank Shugart, was injured, O'Leary was recruited on the spot, based on the recommendation of someone who knew him.

Though there is no independent verification, O'Leary reportedly signed briefly with the team,[4] only to have his arm broken from a pitched ball thrown by 'fireballer' and Hall of Famer Rube Waddell.

[1] In the off-season, O'Leary and teammate Germany Schaefer, known as one of baseball's zaniest characters, worked as a comic vaudeville act.

[1] After finishing his playing career in 1913 with the St. Louis Cardinals, O'Leary became a player-manager in the minor and semi-pro leagues for several years, including in San Francisco, St. Paul, San Antonio, and Chicago,[4] until he was offered a coaching job in 1920 by his close friend, Miller Huggins, manager of the New York Yankees.

Ruth lost control of the car, and O'Leary was ejected from the vehicle, although he suffered only minor injuries.