Merryweather will begin the season on the 26-man roster, Keegan Matheson of MLB.com reports.
The right-hander needed to prove he was healthy after battling back issues in camp, but Merryweather cleared the final hurdle by tossing a scoreless innings Monday in the Jays' last Grapefruit League game. He will likely fill a long-relief role out of the bullpen, but the 29-year-old could still fill key innings, considering the current state of the team's rotation.