Stroman, 24, underwent surgery in March after tearing the ACL in his left knee.
Toronto general manager Alex Anthopoulos discussed the decision at Fenway Park before the team's Tuesday game against the Boston Red Sox.
"He's completely healthy," Anthopoulos said. "That's the first priority and concern for us. Everything we discussed with him has been health, and everything we discussed with our staff has been health. He feels good. We've checked for inflammation, and he's been cleared."
Stroman's return comes at the right time, too. Anthopoulos said Monday's losing pitcher, Mark Buehrle, went back to Toronto to get a cortisone shot in his pitching shoulder. His next scheduled start was pushed back to Tuesday in Atlanta after he was tagged for five runs and nine hits in 3 1/3 innings in an 11-4 loss to Boston on Monday.
"He's done this before," Anthopoulos said of Buehrle. "He's been streaky and came back and pitched really well. The guy's been doing it so long, you don't bet against him."
Stroman made two minor league rehab starts. He gave up four runs on eight hits over three innings in the second one Monday for Triple-A Buffalo.
"We've gone slow with him, and he's recovered well," Anthopoulos said. "He wouldn't have been out there, and he wouldn't have thrown (simulated) games or rehab starts if there was any concern at all."
At the time of the injury, Stroman was expected to miss the entire season.
Stroman was 11-6 with a 3.65 ERA in 26 appearances (20 starts) as a rookie in 2014.