BOSTON — White Sox right-hander Michael Kopech underwent surgery Friday morning to remove a cyst from his right knee and was placed on the 15-day injured list, ending his season with nine games remaining.
The Sox recalled right-hander Yohan Ramírez from Class AAA Charlotte.
Kopech, 27, had the procedure performed at Rush Oak Brook Surgery Center by Dr. Nikhil Verma, White Sox lead team doctor. Full recovery time is expected to take between 6-8 weeks.
Kopech struggled this season with a 5-12 record and 5.43 ERA. Kopech had surgery to repair a torn meniscus on the same knee at the end of last season.
Ramírez, 28, posted a 3.67 ERA in 26 relief appearances over three stints with the Pirates this season before being designated for assignment on September 1. The Sox claimed him off waivers on Sept. 5 and sent him to Triple-A Charlotte, where he allowed four earned runs over 4 2⁄3 innings.
