Right-handed reliever Joe Kelly exited the White Sox game against the Red Sox during the eighth inning Wednesday with an apparent injury.
Protecting a 3-1 lead, Kelly struck out Trevor Story looking and Franchy Cordero swinging to open the inning but winced after the strikeout pitch to Story.
He walked off with assistant trainer Josh Fallin.
Liam Hendriks finished the inning by getting Christian Vazquez to ground out to shortstop Tim Anderson.
Kelly was pitching in his seventh game after starting the season on the injured list with a right biceps nerve injury. He had allowed six runs over five innings.