The Blue Jays recalled Thornton from Triple-A Buffalo on Monday.
He'll join the big club for the first time this season after he had previously been optioned to Triple-A late in spring training. Over 23.2 innings out of the Buffalo bullpen, Thornton pitched to a 3.04 ERA, 1.51 WHIP and 22:14 K:BB. He'll presumably be limited to lower-leverage spots in relief while he's up with the big club.