This marks the 25-year-old McCarthy's first callup of 2017. He pitched 8 1/3 innings in 10 outings last year as a September callup, posting a 6.48 ERA with seven strikeouts and five walks. Over parts of five Minor League seasons, he's compiled a 2.91 ERA with 22 saves. Manager Ned Yost mentioned during Spring Training that McCarthy and Jake Junis could contribute at the MLB level.
The Royals have not yet named a starter for Tuesday's game against the Tigers.
Daniel Kramer is a reporter for MLB.com based in Denver. Follow him on Twitter at @DKramer_. This story was not subject to the approval of Major League Baseball or its clubs.