He was again encouraged by how his arm felt but, although the session might have moved him a step closer to resuming mound work, it did not really bring him closer to a return to the rotation.
Rodriguez feels he'll have a better idea of that timetable once he throws his first bullpen.
"I need to throw a side, hard. After a bullpen I'll be able to tell you guys more about how I feel," Rodriguez told reporters.
The Pirates' staff is closely monitoring Rodriguez's long-toss program as they try to determine the next stages of his comeback.
"We do believe there is a progression he needs to go through, completely," manager Clint Hurdle said, "before he gets on the mound, and we are following that. He is very encouraged with the improvement."
Rodriguez is not likely to return before September, at the earliest. Given his lengthy layoff, he would benefit from a rehab assignment, but even that may be out of the question, since Minor League seasons wrap a few days into September and he hasn't yet thrown off a mound.
The Pirates would welcome Rodriguez's veteran contribution down the stretch and even more in the postseason. His injured status would override the requirement for players to be on the Aug. 31 active roster for postseason eligibility.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. Steven Petrella is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.