BALTIMORE -- Zac Lowther returned to the Orioles on Monday afternoon for his second big league start armed with cleaner mechanics and a healthier left shoulder. After pitching six innings of one-run ball in a 3-2 loss to the Royals at Camden Yards, he probably won’t need to wait as long for his third MLB start.

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In his first appearance in the Majors since July 7, the left-hander allowed one run on three hits and two walks in his longest outing at any level in 2021. He rebounded from his only blemish -- a 3-1 fastball that former Oriole Hanser Alberto swatted into the O’s bullpen -- by retiring the last five batters he faced.

The result was the best of Lowther's six big league outings, a performance that lowered his ERA nearly four runs to 6.91.

“I thought he threw the ball really well,” said O’s manager Brandon Hyde. “I’m really happy with the strikes -- he worked ahead of hitters. I liked the tempo on the mound. … He looked a little sharper than when he was up here previously.”

Lowther’s callup from Triple-A Norfolk marks his fourth stint with Baltimore. But it’s his first since working back from a left shoulder strain he sustained in Triple-A, which kept him out for several weeks and may have been a blessing in disguise.

“The injury kind of gave me a good reset,” Lowther said. “I was able to go down to Florida and get my body right, get my mind right. And then as I worked my way back up, I was able to kind of feel out what I needed to work on and what would get me back to Baltimore.”

Salvador Perez and Andrew Benintendi singled in runs in the eighth off reliever Cole Sulser (4-4), who was working for a third time in four days, to put the Royals ahead. Hyde turned to Sulser in part because of what transpired an inning earlier, when Jorge López turned his right ankle making a play at first base to record his only out.

“I was hoping Lopy could go into the seventh there, possibly even the eighth,” said Hyde, who added that the extent of López’s injury would be known later Monday or on Tuesday.

The O’s offensive contributions on Monday came from two players. Austin Hays singled in a run for Baltimore in the third. Cedric Mullins doubled in the first and homered in the fifth, a day after the All-Star center fielder became the first Oriole to join baseball’s 25-25 club since Reggie Jackson in 1976.

Lowther’s second start was essentially the polar opposite of his first, in which he allowed seven runs in 2 1/3 innings in an 11-6 loss to Boston on May 8. This time, the southpaw gave a performance just shy of dominant while throwing 56 of his 92 pitches for strikes.

After he followed Alberto’s solo shot by hitting Hunter Dozier, Lowther got Whit Merrifield to ground into a crucial double play to help him escape the fifth. Then he got three flyouts in a clean sixth, finishing a strong case to take another turn in a patchwork Orioles rotation.

“I just want to show them there was a reason I was put on this team,” said Lowther. “And just be able to go out there and do everything that got me to this point.”

Said Hyde: “I think he got a little taste up here early in the year and understood the adjustments he needed to make."