The New York Yankees drafted Spence in the 10th round, with the 315th overall selection, of the 2019 Major League Baseball draft.[4] He made his professional debut with the rookie–level Pulaski Yankees, posting a 3.54 ERA in 16 games out of the bullpen. Spence did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[5]
Spence returned to action in 2021 with the High–A Hudson Valley Renegades. He made 23 appearances (20 starts) and logged a 7–6 record and 3.94 ERA with 118 strikeouts in 105 innings pitched.[6] He split the 2022 season between the Double–A Somerset Patriots and Triple–A Scranton/Wilkes-Barre RailRiders. Pitching in 27 contests, Spence registered a 6–7 record and 4.70 ERA with 127 strikeouts across 130+1⁄3 innings of work.[7]
The Yankees invited Spence to spring training as a non-roster player in 2023.[8] He spent the year with Triple–A Scranton, making 29 starts and posting an 8–8 record and 4.47 ERA with 153 strikeouts across 163 innings pitched.[9]
Oakland Athletics
On December 6, 2023, the Oakland Athletics selected Spence with the first overall pick of the Rule 5 draft.[10] After competing in spring training in 2024 for a roster spot with the Athletics,[11] Spence made their Opening Day roster.[12] After pitching in relief, Spence made his first major league start on May 17.[13] The Athletics kept him in their starting rotation afterwards.[14]