Paulino's latest setback will sideline him for at least a week and maybe longer, but his upper arm appears to be sound, which is the bigger concern.
Paulino, who was examined by team medical director David Lintner on Friday morning, has missed the entire season rehabbing a pinched nerve in his right arm. His recent problem, however, has nothing to do with that injury.
"As long as it's unrelated to the problem that required us to shut him down during Spring Training, in that respect, it's not great news, but it allows us to still be optimistic that he can pitch competitively at some point before the end of the year," general manager Ed Wade said.
Paulino left his first rehab outing earlier this week after two-thirds of an inning when he felt soreness in his shoulder. He was scheduled to pitch on Friday in Round Rock, but following the advice of Lintner, he will rest instead.
"We'll back him off until it cools down," Wade said.
In other injury news, right-hander Geoff Geary threw lightly off the mound before Friday's game and gave the thumbs up as he retreated into the clubhouse, indicating that he is available to pitch.
Geary has been sidelined with a groin strain, an injury he sustained during the Astros' rain-shortened win over the Cubs on Monday.
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.