"Let's see how he gets through Sunday," Rangers manager Jeff Banister said.
Banister said Darvish could get a third rehab start or the Rangers could put him back in the rotation after the All-Star break with the idea of limiting him to 75-80 pitches in his first start.
Darvish last pitched on Monday, throwing 42 pitches over two-plus innings in a start for Frisco. The Rangers weighed the possibility of bringing back Darvish on Saturday with four days rest but preferred to give him an extra day.
"Given this is a guy who works well on an extra day of rest, we wanted to give him the extra day," Banister said. "Let him go get his work on something, I don't want to say he's used to, but works better under those conditions. Give him the extra day and make sure there is no soreness."
Kela has made two one-inning relief appearances in the Minors, one for Frisco and one for Triple-A Round Rock. Both were scoreless as he has allowed one hit and struck out four. He threw 18 pitches in both outings.
"I think I'm doing all right," Kela said. "I feel good about my outings. I threw a few more pitches than I should. I had a bunch of strikes but putting guys away early is what I'm looking for. But my body feels good…I'm feeling really good."
Kela, who last pitched for the Rangers on April 19, is scheduled to pitch back-to-back games on Saturday and Sunday for Frisco. If all goes well, he could be activated on Friday when the Rangers open the second half against the Cubs.
"I feel ready," Kela said. "If they put me on the roster tonight, I could pitch with everything I have. But we have a different plan so I'm going to respect the process and trust the process."
Holland resumes throwing: Left-hander Derek Holland, who is on the disabled list with inflammation in his left shoulder, resumed his throwing program on Friday. Holland played catch for 25 tosses and felt no issues.
"I felt great," Holland said. "I feel like a champion."
The plan is for Holland to go through two weeks of a progressive throwing program, starting at playing catch and leading up to working off the mound in the bullpen.
• The Rangers optioned right-handed starter Chi Chi Gonzalez to Triple-A Round Rock on Friday and called up left-handed reliever Alex Claudio. The Rangers don't need a fifth starter until July 19 and Claudio gives the Rangers an extra reliever out of the bullpen.
• Mitch Moreland was out of the lineup Friday for the sixth straight game with tightness in his right calf. Moreland is still available as a pinch-hitter and Banister said there are no plans to put him on the disabled list.
• Frisco was auctioning off game-worn hats and jerseys from Friday and Saturday's games to benefit Assist the Officer Foundation, which assists the families of the police officers killed on Thursday night in Dallas. Ten percent of all revenue from the team's store on those nights will also go to the Foundation.