Cam Booser’s four-seam fastball averages 95.8 mph, so it was a bit unusual when one clocked in at just 92.9 mph on Thursday against the St. Louis Cardinals.

The pitch was launched 404 feet for a two-run home run by Willson Contreras to tie the game in the eighth inning, which continued with Booser allowing what turned out to be the game-winning run in a 5-4 loss.

“We will check him out. He was, the velo was down,” White Sox manager Will Venable said of Booser after Game 1 of the doubleheader. “We’ll check him out here between games and see where he’s at and get him evaluated just to make sure he’s alright.”

One day later, Booser was placed on the 15-day injured list with a left shoulder strain. The White Sox also lost starting pitcher Davis Martin to the injured list on Friday with a right forearm strain. They’ve been replaced by minor league pitchers Wikelman Gonzalez and Jake Palisch, who are in line to make their major league debuts.

The White Sox acquired Booser, 34, in December as part of a trade with the Boston Red Sox in exchange for right-hander pitcher Yhoiker Fajardo. In 30 appearances out of the White Sox bullpen in 2025, Booser posted a 5.11 ERA and a 1.41 WHIP with 14 walks and 27 strikeouts in 24.2 innings.