Nelson (hamstring) made the fourth appearance of his rehab assignment Tuesday with Double-A Reading, tossing five innings and striking out four while allowing an unearned run on six hits and no walks.
Nelson has made all but four of his 69 career MLB appearances as a reliever, but the Phillies have been getting him stretched out a starter since he began his rehab assignment April 18. He's scheduled to make another rehab start Sunday, likely with either Reading or Triple-A Lehigh Valley. The Phillies don't have a rotation spot available for him at the moment, so Nelson will likely be optioned to Triple-A once his 30-day rehab window closes and he's officially activated from the 15-day injured list.