[2] At the age of 19, he made his professional debut on August 22, 1891 for the Baltimore Orioles near the end of their 1891 season in the last year of the American Association.

For the Orioles, he played second base, right field, and shortstop for a total of eight games.

The following year, O'Connell was not a member of the Orioles when they transferred to the National League in 1892.

[2] The Tigers struggled in their second season in the American League and were constantly changing their roster, which was largely filled with young, inexperienced, and inexpensive rookies.

[3] O'Connell, like many other players from the 1902 Detroit Tigers, did not return to play the next year.