The Giants entered Wednesday's series finale against the Pirates on a four-game losing streak, but they did receive good news prior to first pitch.
Jake Peavy threw 40 pitches in a bullpen session and will make another rehab start for Triple-A Sacramento on Saturday.
"He's feeling a lot better with that lower back, and that's good news for us," Bruce Bochy told reporters. "So it looks like he can resume his rehab and hopefully he can stay away from any more setbacks and get him ready here.
"It's gonna take a few starts for him because he did have a little setback here, but the good news is he thinks he's gotten over the hump where it was bothering him there."
After tossing 3.1 scoreless innings during his first rehab outing with Single-A San Jose, Peavy allowed six runs on nine hits for the River Cats on May 28.
Two days later, he felt some minor back tightness and the Giants elected to "slow-play" it with Peavy.
"I've just got to get stronger," Peavy said last Friday. "I haven't been able to get as strong as I need to be at this point in time. Yesterday was probably the best work day I've had, in terms of doing legs ... And I need some time on the mound to get comfortable with throwing off-speed pitches and getting that fastball command back.
"This is a long season. I'm trying to stay positive and think about how this plays out for the best."
Peavy hit the disabled list on April 18.
He's 0-2 with a 9.39 ERA through two starts this season.