Sampson (knee) completed his third rehab start at Triple-A Iowa on Saturday, tossing three innings and striking out two while allowing three earned runs on three hits and one walk.
Sampson began his rehab program in the rookie-level Arizona Complex League on June 24 and has now made five appearances in total during the minor-league assignment, pitching to an 8.56 ERA and 1.39 WHIP in 13.2 innings. Since the Cubs don't appear to have a spot in the rotation available for Sampson, he'll likely remain on the farm for close to the full 30 days of the rehab assignment before being activated from the 60-day injured list. Sampson has three minor-league options remaining, so he could be optioned to Iowa once he's reinstated in order to continue making starts with the hope that a spot in the big-league rotation reopens at some point.