"Doctor said yesterday that I need go day by day, see how it feels and we'll start the rehab assignment again," Perez said.
Perez, who is recovering from May 2014 Tommy John surgery, threw 2 2/3 innings Wednesday for Double-A Frisco, allowing one run on five hits with no walks and four strikeouts.
Perez said he felt the tightness in his groin in the second inning and it got worse in the third. The tightness was still there when Perez tried to throw Friday.
"I didn't want it to get terrible," Perez said. "I want to be healthy."
This setback could come with consequences for Perez, who is essentially in a race with Matt Harrison for a potential spot in the Rangers' rotation. Harrison, who is coming back from a June 2014 spinal surgery, is scheduled to make his third rehab start Sunday for Triple-A Round Rock.
• Elvis Andrus hit his third home run of the season Friday. The Rangers are 3-0 this season in games in which Andrus has homered and have won the past seven games when Andrus has gone deep.
• The Rangers entered Saturday 6-1 in their past seven games at Globe Life Park after starting the year with a 6-14 home record.
• Texas starters' eight consecutive quality starts through Friday is the fourth-longest streak in club history.
Cody Stavenhagen is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.