Righty Casey Lawrence was optioned to triple-A Buffalo after Toronto won the doubleheader's first game 7-3 in Baltimore on Monday.
Catcher Zack Collins was designated for assignment after the victory.
The moves come after right-handed reliever Zach Pop was recalled by the Blue Jays from triple-A to be the team's 29th man in the day-night doubleheader against the Orioles on Monday morning.
Toronto's playoff hopes hang in the balance in the four-game series in Baltimore as the Orioles trail Toronto by 3.5 games in the American League wild card race following the afternoon loss.
Merryweather has been out with a left abdominal strain since June 14.
The 30-year-old Merryweather has a 6.38 earned-run average over 18 1/3 innings for Toronto this season with 17 strikeouts.
Lawrence has an 8.04 ERA over 15 2/3 innings with nine strikeouts for the Blue Jays. Collins is hitting .194 over 72 at bats this season in the major leagues.
Pop, from Brampton, Ont., has pitched 6 2/3 innings for the Blue Jays so far this season, allowing nine hits and two runs with one strikeout. Pop was acquired by Toronto in a trade with the Miami Marlins on Aug. 2.
Infield prospect Jordan Groshans was sent to Miami for Pop, fellow reliever Anthony Bass, and catcher Edward Duran.
This report by The Canadian Press was first published Sept. 5, 2022.
The Canadian Press