SAN FRANCISCO -- Sean Manaea was bumped from the Giants’ rotation following a rocky start to the season, but the veteran left-hander is making a case to start again now that he’s gotten back on track while working out of the bullpen. 

Manaea did the heavy lifting in the Giants’ bullpen game on Tuesday night, allowing only one unearned run over four innings in a 2-1 loss to the Pirates at Oracle Park.

After logging a 7.96 ERA over his first eight outings (six starts), Manaea has yielded only one earned run over 10 2/3 innings (0.84 ERA) with 16 strikeouts in his last four relief appearances. 

“I think he’s really adjusting to the role well,” manager Gabe Kapler said. “I think he’s bouncing back from his outings well. He’s made some adjustments, but most importantly, he’s more confident than he has been all year. It’s showing in the way that the ball is coming out of his hand. The bite on his breaking ball has improved, as well.”

San Francisco’s relievers have posted an MLB-best 0.80 ERA over the club’s last 15 games, but they didn’t receive enough support from their bats, which produced only five hits against right-hander Johan Oviedo and four Pirates relievers.

The Giants, who erupted for 14 runs in Monday’s series opener, put at least one man on base in each of the first eight innings, but they finished only 1-for-8 with runners in scoring position, with their lone run coming on Michael Conforto’s RBI single off Oviedo in the bottom of the first.

“There are going to be nights when we’re not able to cash in on those,” Kapler said. “I thought we had a good quality first inning. We had a couple of moments where we were threatening. We just weren’t able to get the big hit.”  

John Brebbia got the starting nod on his 33rd birthday, but he surrendered a two-out solo shot to former Giant Connor Joe in the first inning, marking the first run he’s allowed in four opening assignments this year. Brebbia faced only three batters before giving way to Manaea, who struck out Jack Suwinski looking on a 95 mph fastball to end the inning.

Manaea cruised through the next three innings before running into trouble in the fifth, when the Pirates put runners on second and third with one out following an error from left fielder Mitch Haniger, who allowed Jason Delay’s hard-hit single to skip over his head. Pittsburgh capitalized on the miscue, as Rodolfo Castro subsequently scored the go-ahead run from third after Manaea yanked a slider that got past rookie catcher Patrick Bailey for a wild pitch. 

Bailey managed to quickly corral the ball and throw to Manaea at the plate, but Manaea couldn’t hold on after being upended by Castro’s headfirst slide, giving the Pirates a 2-1 lead.

“Unfortunately, I had it and then it got knocked out,” Manaea said. “Obviously, that was the crucial part of the game. It sucks.”

Manaea managed to limit the damage with the help of Bailey, who blocked the plate with his left foot and tagged Delay to get the out at home on the next play. Bailey then picked off Josh Palacios with a perfect throw to first for the final out of the inning.

“He can throw from any angle,” Kapler said. “He’s very athletic back there. On a ball that seemingly was in the dirt, to be able to pick it and get that throw off as quickly as he did was really impressive.” 

“He’s gross back there,” Manaea added.

Manaea was charged with the tough-luck loss, but he still saw positives in his longest relief outing of the year. He was particularly pleased with his slider, which induced four swinging strikes and had more horizontal movement following a slight grip change. 

“Today was kind of a sweepy guy,” Manaea said. “I just felt like I could control it and throw it for a strike. That’s ultimately the main goal, to be able to do that on a consistent basis. The more confidence I have in that the better it will be in the long run. Today it felt really good.”

Would the Giants consider moving Manaea back into the rotation if he continues to build on his recent turnaround? 

“I think everything will always be on the table for us,” Kapler said. “We’ll just keep evaluating it at every turn.”