Contreras was optioned to Triple-A Indianapolis on Tuesday.
After allowing multiple runs in each of his last three starts, Contreras will finish the 2022 season in the minors. He put up a 3.79 ERA and 1.27 WHIP in the majors this season and will likely be back on the major-league roster to start 2023. JT Brubaker (arm) was reinstated from the 15-day injured list in a corresponding move.