SAN FRANCISCO — Two weeks ago, Dean Kremer delivered the best start of his season, twirling seven scoreless innings against the Astros.

That start extended the best stretch of success in Kremer’s career, lowering his ERA below 4.00 and showcasing the right-hander’s evolution amid a deflating campaign for the ballclub. Since, Kremer has put up two of the worst starts of his season, inflating his ERA to 4.52 and reviving doubts about his consistency.

Kremer on Friday was tattooed by the Giants and pitched a season-low three innings en route to the Orioles’ latest sloppy and undisciplined defeat, this one the club’s fifth straight. He surrendered nine hits and seven runs, and Baltimore’s bullpen was just as bad in allowing nine hits and eight runs in the 15-8 loss.

Kremer’s disastrous outing follows his start last weekend against Houston in which he gave up three homers and seven runs in five innings. In his 19 previous starts, Kremer posted a sparkling 3.16 ERA.

The Orioles (60-75) would have preferred if Kremer’s performance was the worst part of the evening that opened the club’s six-game West Coast road trip. Instead, it was sloppy play from the defense in the seventh inning that turned a regular loss into yet another laugher.

“I thought the position player group played great for six innings. That seventh inning was ugly, without a doubt,” Orioles interim manager Tony Mansolino said. “We’ve seen our guys do that this year where games get out of hand and we don’t help ourselves in a lot of ways, and that happened right there. And other teams around the league do that, too. We’re not the only ones.”

Baltimore made three errors in the frame, resulting in four unearned runs against lefty reliever Grant Wolfram. Jackson Holliday was unable to field and flip a grounder up the middle for a force out at second base as the 21-year-old’s defensive struggles continued. Dylan Beaves’ throw home on Rafael Devers’ RBI single was nowhere near the plate, allowing a runner to advance. And Emmanuel Rivera bounced a throw to first base on a routine play at third.

“You play so many games, it’s bound to happen,” Mountcastle said of the sloppy defense. “We’ll clean it up a little bit and go back out there tomorrow and play well.”

Despite the way the game ended, the Orioles actually held an early lead off left-hander Robbie Ray. Ryan Mountcastle’s RBI double in the first scored Holliday, who walked to lead off the game and stole second, to put Baltimore up 1-0. Mountcastle led the offense, going 3-for-5 with another RBI double in the third and a two-run single in the fifth. Rivera’s two-run single in the third, Coby Mayo’s solo shot in the eighth and Luis Vázquez’s RBI groundout in the ninth brought home the rest of Baltimore’s runs.

Kremer allowed the first four batters he faced to reach base, including two via walk. Matt Chapman’s RBI single, Dominic Smith’s sacrifice fly and Luis Matos’ two-run single put San Francisco (67-68) up 4-1 at the end of the first. The Giants scored two more in the second (Devers RBI single, Chapman sac fly) and another in the third (Drew Gilbert RBI double) off Kremer.

“That’s a part of the game,” Kremer said about many of the hits off him being seeing-eye singles. “Some days they find the fielders, and some days they don’t. Today was not one of those days where they find the fielders.”

Facing reliever Corbin Martin in the fourth, Smith launched a two-run homer that landed in McCovey Cove for the 107th splash hit by a Giants player since Oracle Park opened in 2000. Matos (4-for-5) homered off Martin in the fifth, and Willy Adames (4-for-6) started the rally in the seventh with an RBI single. Smith tallied his fourth RBI with a single to cap off the scoring in the seventh, and Gilbert smacked another RBI double in the eighth as the Giants won their sixth straight.

Postgame analysis

Mountcastle is the odd man out? Not so fast.

There’s no hiding that it’s been a disappointing season for Mountcastle, whose OPS has been under .700 all season. But that can be said for almost everyone on the Orioles.

With youngsters Samuel Basallo and Mayo on the roster and the need to have Adley Rutschman and Tyler O’Neill at designated hitter, it’s not difficult to infer that Mountcastle’s days as an Oriole could be numbered. He’s entering his final year of arbitration and would be due to make about $8 million.

Perhaps that price tag will be too much for the Orioles, especially for a player that would likely be in a part-time role. But Mayo has still yet to get going in the big leagues with a .189 batting average and .603 OPS this season. Basallo will split time between three spots. And O’Neill’s injury history makes him a question mark. Meanwhile, Mountcastle has hit .293 with a .725 OPS since May 1.

The Orioles need good right-handed hitters to contend for a playoff spot in 2026. Mountcastle might not neatly fit into those plans, but it shouldn’t be a foregone conclusion that he doesn’t.

What they’re saying

Mansolino on the importance of injured players returning:

“I think it’s more mental than anything. Just the fact that you come back and you play in a big league game and you finish out the year with your buddies, with your boys, with your teammates, I think that’s important. But then, it indicates that you’re healthy at the end of the year. So you enter the offseason as a healthy player, which means you’re taking time off, your body’s recovering, you’re starting your normal cycles of hitting, throwing, whatever they do, at the normal time, versus if you finish the year on the shelf, then you’re continuing to rehab and your normal cycles might not be the same.”

By the numbers

Friday was the Orioles’ 135th game this season. They’ve used 123 total batting orders, including a new combination Friday with Rivera in the No. 5 hole, Beavers batting eighth and catcher Alex Jackson in the No. 9 spot. While that number is high, it’s on pace to be lower than the 144 combinations used last year and the 150 used in 2023.

On deck

The Orioles on Saturday will look to end their five-game losing streak, and they have an excellent chance to do so with Trevor Rogers on the mound. The southpaw will enter the afternoon game on the West Coast with a 7-2 record and a 1.40 ERA that ranks best in baseball since his season debut May 24.

Around the horn

• O’Neill received a second injection in his wrist after his first attempt at swinging at bat resulted in soreness, Mansolino said pregame. O’Neill, who is on the injured list for the third time this season, is back in Baltimore and is expected to swing a bat again this weekend. The slugger has played only 43 games this season after signing a three-year, $49.5 million contract over the offseason.

• Starting pitcher Tyler Wells is expected to make his season debut next week in San Diego against the Padres. The Orioles are moving to a six-man rotation. If their starters remain on turn, Wells would start Tuesday between Kyle Bradish on Monday and Cade Povich on Wednesday. Wells hasn’t pitched since April 2024 when he injured his elbow and then two months later underwent surgery.

• Mansolino maintained that Rutschman (oblique) could return before the end of the season. “My hope is, yes, he’ll be back and hopefully play 10 days, two weeks would be great if we get to that point,” Mansolino said.

• Jordan Westburg (ankle) is with the team in San Francisco, and Mansolino said that’s an indication that the third baseman is approaching a return to the field. “If he plays on this road trip, he’s exceeding expectations. I think it’s more likely to play some type of baseball when we get back home,” Mansolino said.

Have a news tip? Contact Jacob Calvin Meyer at jameyer@baltsun.com, 410-332-6200 and x.com/JCalvinMeyer.