The Royals recalled McArthur from Triple-A Omaha on Tuesday, Anne Rogers of MLB.com reports.
After the Royals unloaded Scott Barlow and Ryan Yarbrough ahead of Tuesday's trade deadline, McArthur and Jackson Kowar will both come up from Omaha to fill in the holes in Kansas City's bullpen. McArthur holds a 5.26 ERA through 49.2 innings in Triple-A this season and surrendered seven runs during his MLB debut in June.