The Blue Jays optioned Mayza to Triple-A Buffalo on Thursday, Scott Mitchell of TSN.ca reports.
Non-roster invitees Tyler Clippard and John Axford beat Mayza out for the final two spots in the Toronto bullpen. The left-handed Mayza had a rough go of things in his first exposure to the big leagues in 2017 with a 6.88 ERA and 1.65 WHIP across 17 innings, though a 27:4 K:BB, .501 BABIP and 60 percent strand rate all point to him being highly unlucky.