Corbin Burnes returned to form on Sunday. The Orioles’ offense did not.

Baltimore (82-62) squandered a quality start from its ace Sunday, failing to push a run across in a 2-0 home loss to the Tampa Bay Rays. A two-run home run by Rays left fielder Jonny DeLuca broke a scoreless tie in the sixth inning for the lone blemish against Burnes, who put together his best start since July 30. However, the blast proved to be enough as right-hander Zack Littell threw five scoreless frames and the Tampa Bay bullpen slammed the door shut.

“Really since the All-Star break it’s been a challenge,” manager Brandon Hyde said. “Tough time offensively. Guys are swinging a little bit frustrated and pressing. Trying to do way, way, way too much. Way too many big swings.”

The month of August wasn’t kind to Burnes, the Orioles’ prized offseason addition who had performed up to his billing as an American League Cy Young Award contender over the first four months of the season. He then turned in a 7.36 ERA over five starts in August, his worst statistical calendar month since 2019. After showing signs of improvement in his previous start Monday against the Chicago White Sox, he looked much more like an ace Sunday afternoon.

Burnes, 29, scattered seven hits and two walks with three strikeouts. He stranded six base runners, including two in scoring position in the second. Catcher Adley Rutschman threw out second baseman Christopher Morel trying to steal in the first — just the fifth time the Orioles have caught a runner stealing with Burnes on the mound this season — but the Rays pulled off a double steal the next inning. Burnes then struck out catcher Ben Rortvedt swinging on a looping curveball to end the threat.

He kept the Rays off the board until the sixth when a leadoff walk to first baseman Jonathan Aranda cost Burnes. With Aranda on first, DeLuca clobbered a hanging slider 412 feet over the extended Camden Yards left field wall. Burnes finished the inning at 93 pitches, 20 of which were fouled off by Tampa Bay hitters — fourth most in a game by any opponent against him this season.

“The difference in the game was one swing of the bat today,” Burnes said. “Threw the ball pretty well, got a lot of weak contact. A lot of weak contact went for hits today, but kind of how it goes. The 1-1 slider wasn’t a bad pitch, kind of went down and got it and put a good swing on it, and that was the difference today.”

Relievers Matt Bowman and Keegan Akin kept the score at 2-0 with three scoreless frames between them, putting the Orioles in position to win their finale with the Rays and clinch a third consecutive series victory. But their offense again lacked consistency and couldn’t come through with runners in scoring position. Gunnar Henderson recorded his fourth multihit game of September with three singles and Cedric Mullins stayed hot (.856 OPS since June 9) with a pair of singles, yet those were the only hits Baltimore could muster.

An announced crowd of 29,519 gained hope in the eighth when the pinch-hitting Coby Mayo drew a leadoff walk and Henderson followed with an infield single. That hope was short-lived as Rays relievers Garrett Cleavinger and Edwin Uceta combined to strike out Rutschman, Eloy Jiménez and Anthony Santander in order. Mayo then took over at first base in the top of the ninth to make his first MLB appearance there.

“The swings are looking too hard right now,” Santander said. “We have to be shorter to the ball and put the ball in play, especially with runners in scoring position.”

Uceta returned for the ninth and retired the side to secure the shutout, Baltimore’s sixth of the season. The loss halts any momentum the Orioles gained from their series wins against the Colorado Rockies and White Sox over the last week, adding pressure to find a spark on the road Monday when they open a three-game series against the Red Sox in Boston.

Around the horn

Orioles reliever Danny Coulombe will make his first rehabilitation appearance with Triple-A Norfolk on Wednesday, pitching coach Drew French announced before Sunday’s game. Coulombe, 34, has been out since June 8 and had surgery to remove bone chips in his throwing elbow. The left-hander has a 2.42 ERA in 29 games this season as a key piece in the back end of the Orioles’ bullpen.

Baltimore is also nearing a potential return for right-hander Jacob Webb, who will pitch for Norfolk on Tuesday in his third rehab appearance since hitting the injured list with elbow inflammation. Webb, 31, has a 3.08 ERA over 53 appearances, a total that led the team when he landed on the IL.

The club announced its probable starting pitchers for the upcoming road series in Boston. Rookie Cade Povich will take the ball for the opener Monday followed by Albert Suárez and Dean Kremer. The Red Sox have lined up Brayan Bello, Kutter Crawford and Nick Pivetta to start against them, respectively.