Pearson was diagnosed with a lat strain Friday, Arden Zwelling of Sportsnet.ca reports.
Pearson has had brutal luck with injuries and illnesses, throwing just 33 major-league innings since his debut at the start of the 2020 season. He'd been building up in Triple-A Buffalo since late June after missing the start of the season due to mononucleosis, but he only made it through four appearances before suffering yet another setback. The Blue Jays have yet to provide a timeline for his return.