In 2022 in 29 starts split between Double-A Amarillo and the Triple-A Reno Aces, he was 11–7 with a 3.83 ERA, and led the minors in innings pitched, with 167, as well as strikeouts, with 218.[8] Pfaadt began the 2023 season in Reno, posting a 3.91 ERA with 30 strikeouts across 5 starts.
On May 3, 2023, Pfaadt was selected to the 40-man roster and promoted to the major leagues for the first time to serve as the starting pitcher against the Texas Rangers.[9][10]