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Chicago White Sox right-hander Michael Kopech exited his start on Monday against the Kansas City Royals (KC 6, CWS 4) after facing four batters because of left knee soreness, the team announced. On Tuesday, he was placed on the injured list with a left knee strain. Lefty Tanner Banks was called up to replace Kopech on the roster, the White Sox announced.

Kopech was visited by manager Tony La Russa, pitching coach Ethan Katz, and a trainer before he made his first pitch. He was then allowed to start the game despite showing signs of being compromised. He faced four batters, walking two of them and hitting another, and saw his average fastball velocity clock in at 91.7 mph, or three ticks below his seasonal norm.

Kopech was replaced by right-hander Jimmy Lambert.

It's unclear what ailed Kopech on Monday, but he has dealt with right knee discomfort throughout the season. He had to leave a start in June after feeling a "pop," and an MRI later confirmed that he had a fluid buildup in that knee, but that there was no structural issue to be concerned about.

Kopech, 26 years old, entered Monday sporting a 3.25 ERA (122 ERA+) and a 1.85 strikeout-to-walk ratio in his first 22 starts this season. He's already cleared the 100-inning mark for the first time since 2018, when he threw 126 innings at the Triple-A level. He's since missed significant time because of Tommy John surgery.

The White Sox, a disappointing 62-60 on the year, trail the Cleveland Guardians by three games in the American League Central. They're also one game behind the Minnesota Twins in the division, and four games back in the wild-card race.

La Russa's questionable handling of Kopech comes just days after the manager issued yet another intentional walk in a two-strike count.