Pearson was diagnosed Thursday with a Grade 1 right groin strain, Hazel Mae of Sportsnet reports.
Pearson suffered the injury during his spring debut Monday against the Pirates. The Blue Jays don't sound particularly concerned, but they understandably intend to be cautious with their top pitching prospect. He's been shut down for now. While the team hasn't yet commented on his availability for Opening Day, it was always likely Pearson would have his innings managed in some form this season, so it's possible he's brought along slowly and starts the year on the injured list.