The White Sox acquired right-hander Mike Mayers from the Royals on Wednesday in exchange for cash considerations.
Mayers, 31, has pitched in eight major-league seasons with the Cardinals, Angels and Royals. At Kansas City this season, he appeared in six games including two starts, posting a hefty 6.15 ERA after signing a minor-league deal in the winter.
With Triple-A Omaha, Mayers had a 6.80 ERA in 12 games, including eight starts.
Mayers owns a 12-11 career record with a 5.21 ERA and five saves.
The Sox, who take a 38-54 record into action Friday after the All-Star break, were thin on starting pitching depth behind their starting rotation of Dylan Cease, Lucas Giolito, Lance Lynn, Mike Clevinger and Michael Kopech to start the season, then lost likely No. 6 starter Davis Martin to injury.
With Giolito, Lynn and Clevinger all possible trade targets as the team goes into likely sellers mode ahead of the Aug. 1 trade deadline, the Sox would likely need to rely on their pitching depth to fill innings. Trades could also deplete the bullpen depth with veterans such as Kendall Graveman, Joe Kelly and Reynaldo Lopez potentially drawing interest from contending teams.
Mayers has been pitching in relief for Omaha after getting designated for assignment by the Royals in June, clearing waivers and accepting an outright assignment.
