Mayza was informed by the Blue Jays on Sunday that he made the Opening Day roster, Scott Mitchell of TSN.ca reports.
The 29-year-old was in camp as a non-roster invitee, but he impressed during spring training with one hit allowed and a 6:2 K:BB over 6.2 innings. Mayza last pitched in the majors during 2019 when he posted a 4.91 ERA, and he figures to fill a middle-relief role early on for Toronto.