Triple-A Buffalo reinstated De Leon (shoulder) from its 7-day injured list Sunday.
De Leon, who had been sidelined since spring training while recovering from the right shoulder injury, pitched out of the bullpen Sunday for Buffalo, covering 0.2 innings while allowing two unearned runs on one hit. The 30-year-old righty has seen spot action in the big leagues in five of the past six seasons, but his extended absence coupled with his lack of a 40-man roster spot means De Leon is unlikely to get the call to Toronto in September.