O'Conner played in 102 games for the Single-A Bowling Green Hot Rods in 2013, slashing .233/.290/.381 with 14 home runs and 56 RBI.
[8] O'Conner finished the 2014 season with a slash of .278/.316/.466 with 12 home runs and 47 RBI in 101 total games between Charlotte and the Double-A Montgomery Biscuits.
[12] O'Conner split the 2017 season between Montgomery and the Triple-A Durham Bulls, hitting a cumulative .227/.288/.372 with 8 home runs and 44 RBI in 85 games between the two teams.
After his release from the Giants organization, on April 4, 2018, O'Conner was suspended 50 games after testing positive a second time for a drug of abuse.
[19] On December 14, 2019, O'Conner signed a minor league contract with the New York Yankees organization.
[23] On June 14, 2022, O'Conner signed with the Staten Island FerryHawks of the Atlantic League of Professional Baseball.
[24] On May 19, 2023, O'Conner signed with the Charleston Dirty Birds of the Atlantic League of Professional Baseball.
[28] On August 3, 2024, O'Conner signed with the Kansas City Monarchs of the American Association of Professional Baseball.
On January 30, 2025, O'Conner signed with the Long Island Ducks of the Atlantic League of Professional Baseball.