McGowan was named the club's upcoming starter on Thursday -- two days after a strong performance out of the bullpen. The native of Savannah, Ga., will be allowed to throw approximately 80-85 pitches.
The game will mark McGowan's first start since July 2008, after spending more than three years on the disabled list with a variety of shoulder injuries.
"The primary goal is to get him through this year healthy," Blue Jays manager John Farrell said. "Continue to build some pitching backlog, for the sake of a better way to describe it. Starting Sunday and going forward he will be in the rotation."
McGowan officially made his return to the Majors on Tuesday by tossing four-plus innings against the Red Sox. He surrendered three runs, but the club was excited by his mid-90s velocity and impressive slider-changeup combination.
The 29-year-old will be on a strict pitch limit for the rest of the season, but his chance to start provides Toronto with an opportunity to evaluate just how far he has come this season.
"This is ongoing ... hopefully by the end of September we've got a little bit more knowledge than we do right now," Farrell said. "I'm sure that as he goes through a normal offseason, which his body will certainly be ready for, you'd like to think there will be some additional strength gains throughout the course of the offseason."
McGowan made 12 rehab starts for Class A Dunedin and Double-A New Hampshire this season. He allowed 11 earned runs on 31 hits while striking out 35 in 19 2/3 innings.
One of the right-hander's biggest obstacles was being able to pitch at 100 percent capacity without the fear of re-injuring his surgically repaired rotator cuff. That was an ongoing process all season, and another positive move along the way occurred against Boston.
"I think the other night was a major step in that direction," Farrell said. "I'm sure there will be a higher level of confidence once he completes the remainder of this season -- provided that there are no abnormal feelings physically that he has coming out of given starts. As much as we want to know what the end result will be, we can't rush it until we get there."
McGowan is 20-22 with a 4.73 ERA in 76 career games in the Major Leagues. His best year came in 2007, when he went 12-10 with a 4.08 ERA over 27 starts.