Scherzer (thumb) will begin a rehab assignment with Triple-A Buffalo on Friday, Ben Nicholson-Smith of Sportsnet.ca reports.
Scherzer is in line to throw 60-to-65 pitches in what will be his first start since he went down with right thumb inflammation in late March. The 40-year-old will need at least one additional rehab start after Friday's outing before rejoining the Blue Jays' rotation.