Blackburn (finger) will make his next minor-league rehab start Tuesday with Triple-A Las Vegas, Martin Gallegos of MLB.com reports.
The right-hander threw 40 pitches over 1.2 innings during his first rehab start Friday, and he's scheduled to progress to about 45 pitches or three innings Tuesday. Blackburn will likely require another minor-league start or two beyond that outing before being built up enough to join the A's.