Kopech was placed on the 15-day injured list Friday with right knee inflammation.
Kopech had surgery Friday to remove a cyst from the knee and is expected to require 6-8 weeks to recover. The procedure ends a disappointing 2023 campaign that saw Kopech post a 5.43 ERA while leading the American League with 91 walks. He finished the season in the White Sox' bullpen, although the team's plans for his future role aren't clear.