Blackburn (finger) had his rehab start scheduled for Friday with Triple-A Las Vegas postponed because of the blister he developed during his previous outing Sunday, MLB.com reports.
The right-hander continues to play catch for the time being, but manager Mark Kotsay says there's no current timetable for Blackburn's next rehab start. Blackburn had worked up to 62 pitches in Sunday's outing, yet the setback and time off between starts now appears likely to delay his big-league season debut into May.