Morrow was making his second appearance since a season-ending forearm injury last May. On Feb. 28, the right-hander gave up two hits and one run in two relief innings.
"The important thing, I felt good again," Morrow said. "Forearm is feeling really good. I felt loose again. I felt good with my breaking stuff. Fastball command kind of put me in a hole a couple times."
Morrow struck out two, walked one, hit a batter and threw a wild pitch.
"He's big," Blue Jays manager John Gibbons said. "In a lot of ways he's probably the most important guy, because we expected a lot out of him last year. He's got as good an arm as anybody. When he's on, when he's healthy, he's been a good big league pitcher. If he can fill that void, bounce back and have a full season out there where he doesn't go on the DL and you get his 30-plus starts, that will be big for us."
Travis Snider had a first-inning RBI single and a two-run homer in the third off Morrow. Snider spent time on the disabled list last season with a left big toe injury.
"Travis worked extremely hard this winter," Pittsburgh manager Clint Hurdle said. "He's moving so much better. Now that's he healthy and physically ready to go, we'll see where he can take us."
Edwin Encarnacion had a two-run double for the Blue Jays.
Pirates: Jeff Locke was scratched from his start because of right side tightness. The Pirates believe the injury is a minor one.
Locke gave up one hit in two scoreless innings last Thursday against the New York Yankees. The left-hander won eight straight starts in the first half of last season and made the NL All-Star team. But, he went 2-5 with a 6.12 ERA over his final 12 starts and was shut down in September.
Jay Jackson, who filled in for Locke, gave up one hit in two scoreless innings. The 26-year old right-hander, signed to a minor league contract in December, pitched at Double-A and Triple-A for Miami last year.
Pittsburgh starters have not allowed an earned run in five consecutive games, a span of 10 innings.
Blue Jays: Closer Casey Janssen, out with a sore right shoulder, played catch for the second straight day.
Outfielder Colby Rasmus sat out his fourth consecutive game due to a stiff neck.
Ohka, who last pitched in the major leagues in 2009, agreed to a minor league contract with the Blue Jays in December. The 37-year-old was 51-68 for Boston (1999-01), Montreal (2001-04), Washington (2005), Milwaukee (2005-06), Toronto (2007) and Cleveland (2009). He has played in Japan for Yokohama (1995-98 and 2010-11) and Toyama (2013).