The Royals designated Morgan for assignment Thursday.
Morgan owns a 5.12 ERA and 1.71 WHIP across 19.1 innings in the majors this year but has been far more effective at Triple-A, posting a 1.40 ERA and 1.31 WHIP in 25.2 frames. He'll now end up as the roster casualty necessary to clear space on the 40-man roster for Tony Gonsolin (elbow), who signed a major-league deal with Kansas City on Thursday.