WEST SACRAMENTO, Calif. — The Orioles arrived in California as MLB’s hottest team, winners of six straight games. The Athletics, meanwhile, were in a vicious spiral, losers of 20 of their past 22 games.

But the A’s pitched two left-handed starting pitchers this weekend. Therefore, the O’s lost two of three.

Baltimore is on pace to be the worst lefty-hitting team in MLB history, and it showed Sunday in the Orioles’ 5-1 loss to drop the series in Sacramento. Against Jacob Lopez and Sean Newcomb, two southpaws who entered the matinee with a combined 4.97 ERA this season, the Orioles scored one unearned run in seven innings.

“The story’s just left-handed pitching again. Left-handed pitching got us. We’ve got to figure it out,” interim manager Tony Mansolino said. “We know the hitting guys, the players, everyone’s working on it hard. … Just another game where we’ve seen left-handed pitching that shouldn’t beat us up did beat us up. We’ve got to be better.”

The Orioles are now 3-12 against lefty starters (not including openers) this season and 23-26 in all other games. They are hitting .202 with a .558 OPS versus southpaws. That OPS against lefties would be the worst mark by a team in MLB’s divisional era (since 1969). No other team this century has posted an OPS versus lefties below .598.

The club’s historically bad struggles against southpaws is one of the biggest reasons why the Orioles are MLB’s most disappointing team this season. The Orioles faced a lefty starter 13 times in their first 43 games under former manager Brandon Hyde, going 3-10 in them. The start to the Mansolino era was more fortunate, as the Orioles didn’t face a traditional left-handed starter in any of the new skipper’s first 18 games, in which the Orioles went 10-8 to potentially begin the climb out of the cellar.

“I feel like we’re on a good track right now. I feel like there’s a lot of positives,” Mansolino said. “The biggest thing right now is probably solving the left-handed pitching … and just continuing to pitch the way that we have, really over the last couple weeks as opposed to the last few days.”

Baltimore (26-38) went 4-2 on its West Coast road trip. To win 84 games, the minimum to potentially reach the postseason, the Orioles will have to go 58-40 over their final 98 games — a tall task for a team that’s 59-76 since July 9.

“You go on the West Coast for six games, it’s tough,” Mansolino said. “There’s issues with sleeping through the morning, everyone’s up at 6 a.m., the days are long, it’s hot, we haven’t been in the heat. You walk out of this thing 4-2 against a really good Seattle team and a Sacramento team.

“4-2, I’ll take it.”

The Athletics (26-41) took an early 4-1 lead for the second straight day. Unlike Saturday, when the Orioles roared from behind to win 7-4, the bats were lifeless against Lopez and the bullpen. Baltimore dropped the series’ first game against lefty starter JP Sears.

The Orioles’ lone run scored on a throwing error by A’s catcher Jhonny Pereda in the second inning, though that frame ended on a base running blunder from Emmanuel Rivera. The bats went 0-for-8 with runners in scoring position and left eight men on base.

Baltimore right-hander Tomoyuki Sugano pitched the worst start of his nascent MLB career, allowing eight hits and four runs (three earned) in 4 1/3 innings. His defense didn’t help him, as shortstop Gunnar Henderson made two errors in the loss and Rivera couldn’t make multiple plays at first base.

Tyler Soderstrom blooped a two-out single to give the A’s a 1-0 lead in the first inning. Sugano, whose ERA rose to 3.23, allowed three runs in the second on a double from Pereda, Henderson’s error and a single from Jacob Wilson, who is batting .372 and leads MLB in hits.

In the Orioles’ 11 games before arriving in Sacramento, their starting rotation posted a 2.56 ERA. Only one of them featured a starter allowing more than three runs, and Baltimore went 9-2 in those games. This weekend, though, all three of the Orioles’ starters — Dean Kremer, Charlie Morton and Sugano — allowed at least four runs.

“The last three days were hard on our starting pitching,” Mansolino said.

Max Muncy tacked on an insurance run in the eighth with a solo homer off Bryan Baker. The run ended the bullpen’s 22 2/3-scoreless innings streak that dated to last Sunday.

The Orioles had the chance Sunday to win a third straight series for the first time since July. The fact that it’s been that long is an example of how much this club’s struggled over the past year. If the Orioles are going to make the postseason, they’ll have to string together multiple series winning streaks.

“Yesterday we came back to win, and I think we’re in a good spot as a team,” Sugano said through team interpreter Yuto Sakurai. “If we can continue on, that would be great.”

Postgame analysis: As the Orioles circled the drain in May, it put a spotlight back on the slumping Adley Rutschman.

He was supposed to be a generational catcher, but since July, he’s looked nothing like he did over the first two and a half years of his career. It resulted in existential questions about the state of the Orioles and Rutschman’s future.

What’s wrong? Will he ever get out of this slump? Does he need to be optioned to Triple-A?

Over the past few weeks, Rutschman has silenced those questions as he’s returned to being the type of hitter he was before the inexplicable downturn that began in late June 2024.

Rutschman smacked singles in each of his first two at-bats Sunday. Since May 11, Rutschman is slashing .277/.362/.458 — good for an .820 OPS. Those numbers are similar to the ones Rutschman posted in his first two seasons when he was one of the best young catchers baseball had ever seen.

The 2025 season might be lost. The hole they dug for themselves might be too deep to escape. But if Rutschman is back to being Rutschman, that solves one of the many — and biggest — quandaries this season has presented.

What they’re saying: Sugano, a Japan native, on pitching in the California heat:

“Japan is actually even hotter. It’s more humid. In regards to that, I wasn’t really bothered.”

By the numbers: Randy Johnson in 2001 posted a 2.49 ERA and 10.1 wins above replacement, by Baseball-Reference’s estimation, to win the National League Cy Young Award for one of the best seasons from a left-handed pitcher in MLB history. MLB batters hit .203 with a .583 OPS off the Big Unit that year — a little better than the Orioles’ marks off southpaws this season. The Orioles are making every left-handed pitcher they face look like Johnson.

Up next: If the Orioles are going to rediscover the magic that helped them win six straight games before their series loss in Sacramento, they’ll have to do so against the best team in baseball.

After a day off on Monday, Baltimore welcomes the 43-24 Detroit Tigers to Camden Yards on Tuesday for a three-game series. The Orioles will face rookie Sawyer Gipson-Long on Tuesday before going up against Casey Mize (2.91 ERA) and reigning AL Cy Young Award winner Tarik Skubal (2.16 ERA). Baltimore has yet to announce its starters for the series, but it will presumably be Zach Eflin, Cade Povich and Dean Kremer.

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