SAN FRANCISCO – The Tigers rotation has two starters. The Tigers’ bullpen game Friday had two former starters hold the Giants hitless for six innings.

It was as much of a surprise as the warmth of the midsummer sun that emerged over Oracle Park in between the morning and evening marine layers. That the Giants eventually rallied late to send Detroit to a 3-2 loss on former Tiger Mark Canha’s walk-off sacrifice fly seemed almost to script. But as the Tigers head into the home stretch with limited options for innings, the innings relay race is becoming an increasingly important and successful part of their game plan.

Whether you love or hate the bullpen games, whether the procession of pitching is attractive baseball, it’s currently the Tigers’ script more games than not, and it has kept them close on back-to-back nights in walk-off losses.

“Honestly we put the team in a spot to win,” said Beau Brieske, who combined with Kenta Maeda to hold San Francisco to one walk over six hitless innings before the Giants scored in the seventh, eighth and ninth. “It was an unfortunate ending, but something to build off of.”

Maeda was in the Tigers rotation for three months before his struggles led him to the bullpen just before the All-Star break. Brieske was in Detroit’s rotation for much of the 2022 campaign before an ulnar nerve issue in his right arm cost him much of last season. He returned late last year to a reconsideration of his role, and his pitches played up in smaller doses.

After some rough first-inning counts Friday, including a first-inning walk to Heliot Ramos, Brieske settled down and pounded the zone, particularly with his fastball.

“I was happy with the mix and execution and the slight adjustment from the first inning, when I was just missing,” Brieske said. “I felt like I could mix my pitches well, but I was just around the zone, and then came back the second and third [innings] and felt like I was in the zone consistently, just honestly trying to give as much length as possible. [Manager A.J. Hinch] kept saying, ‘Keep going,’ so I was just focused on making pitches.”

Maeda picked up where Brieske left off, retiring his first nine batters -- six on strikeouts -- before back-to-back singles started the Giants’ comeback in the seventh.

“It hasn’t been a drastic change in comparison to a starter role, but I’m just doing my best to get better with pitching and how the ball’s coming out of my hand,” Maeda said through translator Dai Sekizaki. “I’ll still be working on that.”

It marked the third time this season that the Tigers have held their opponent hitless through six innings. Two of those occasions have been with multiple pitchers involved; only Jack Flaherty carried a hitless start through six innings on May 30 at Boston.

This is part of the puzzle that manager Hinch and pitching coach Chris Fetter are piecing together with the arms they have available. Bryan Sammons was in an independent league signing last year whose results at Triple-A Toledo were arguably better than the raw pitches would suggest, earning him a call. Thursday’s loss in Seattle saw him toss 4 1/3 innings of one-run ball.

“His first time through the league, guys are looking at him, and maybe they haven’t seen him, but he does pound the zone,” Hinch said.

Brant Hurter was called up last week with a 5.80 ERA in Toledo’s rotation, but his three scoreless innings last Sunday against the Royals showed the stuff that made him Detroit’s No. 14 prospect.

The bullpen games are allowing Hinch and Fetter to pick and choose their spots for them, both in how the opposing lineup shakes out and how the innings go.

It’s not as great a situation as the Tigers had going into the season, when they had six legitimate starting options led by Tarik Skubal and Flaherty. And to be fair, it’s a temporary fix. Casey Mize, out since the end of June with a hamstring strain, began a rehab assignment Thursday in Toledo and is expected to be ready to step back into his old role in Detroit once he’s eligible to come off the 60-day injured list at the end of August. Reese Olson (right shoulder strain) has progressed in his throwing program and expects to return before the season ends. Matt Manning should return from his lat injury to rejoin the rotation in Toledo, and could get another chance in Detroit if he’s effective.

But for now, the bullpen games are working.