The Royals optioned Loftin to Triple-A Omaha on Monday.
Loftin will cede his spot on the 26-man active roster to Michael Massey (calf), who was reinstated from the 10-day injured list. The 27-year-old utility player had appeared in four of the Royals' first nine games, going 2-for-9 with a double, two walks and three runs.