O'Reilly did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[5] He returned to action in 2021 with Altoona and the Triple-A Indianapolis Indians. In 38 total appearances, O'Reilly logged a 3–5 record and 5.85 ERA with 35 strikeouts across 67+2⁄3 innings pitched.[6]
O'Reilly spent the 2022 and 2023 seasons back with Indianapolis. He posted a 5–3 record and 5.84 ERA with 29 strikeouts over 41 games in 2022, and registered a 3–8 record and 5.74 ERA with 55 strikeouts across 50 contests in 2023.[7] O'Reilly was released by the Pirates organization on September 28, 2023.[8]
Los Angeles Angels
On March 25, 2024, O'Reilly signed with the Irish Wolfhounds Baseball Club, a barnstorming team made up of Irish-American players who either have or qualify for Irish citizenship.[9] However, O'Reilly signed a minor league contract Los Angeles Angels organization April 16.[10] In 27 games (12 starts) split between the Double-A Rocket City Trash Pandas and Triple-A Salt Lake Bees, he accumulated a 4.65 ERA with 69 strikeouts across 79+1⁄3 innings pitched. O'Reilly elected free agency following the season on November 4.[11]