With weeks to go until baseball’s postseason, it’s an especially bad time to lose one of the stalwarts in the lineup.

Fortunately for the Orioles, they might have lucked out with Ryan Mountcastle.

On Thursday afternoon, manager Brandon Hyde said Mountcastle, the 26-year-old right-handed first baseman, was “feeling a lot better” a day after having to leave a game early with left shoulder soreness. Hyde called it “great news” and said Mountcastle might be able to return as soon as Thursday night’s series opener against AL East rival Tampa Bay.

“The imaging was all positive, so it’s just day to day right now,” Hyde said.

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Ryan O’Hearn was listed as the starter at first base Thursday night against Rays right-hander Aaron Civale.

One of the Orioles’ most trusted veterans, Mountcastle has missed extended time this season with vertigo. Since coming back, he’s been one of the best bats. He hit .357 in July and August with seven home runs.

“Such a threat at the plate, and he can go deep at any time and takes at-bats and gets huge runs for us,” Hyde said. “Love to see him back in there. Hopefully he’s back in there soon.”

Heston Kjerstad has been making a case for a big league call-up this season, but he might not be with the Orioles long. (Ulysses Muñoz/The Baltimore Banner)

A quick turnaround for Mountcastle, who Hyde said would not need an IL stint, might spell a short stay in the majors for Heston Kjerstad, who was called up from Triple-A Norfolk for the first time late Wednesday night. Kjerstad was tapped partly as insurance for Mountcastle’s injury, but the power-hitting lefty who chiefly plays outfield has been knocking at the door for some time.

The 24-year-old Texan was not in the starting lineup Thursday night, but he relished his first moments in the big league clubhouse. The No. 2 overall pick in 2020 had myocarditis that delayed the start of his pro career, but he has rocketed up the minors since, hitting .298 with an .870 OPS in Norfolk. His bat was likely what made him the choice over other outfielders in the minors such as Colton Cowser, who was up earlier in the season.

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His parents, siblings and a few friends expected to make the game on last-minute flights.

“They’re pumped,” Kjerstad said. “Mom cried. Dad was super excited. Me and my brothers, you know, we’re pumped, just you know, FaceTiming each other. So it’d be good to see everyone in person and everything like that. So definitely a special moment and thankful to have my family too. You know, they’re a big part to get me here.”

Hyde said it was unlikely Kjerstad, who has played a handful of games at first base, would directly fill in for Mountcastle in the infield, but he would likely be used as a pinch hitter or corner outfielder if he sees action.

The Orioles skew young, so a few players have been Kjerstad’s teammates in the minors, including Mountcastle and Cedric Mullins this summer during rehab stints. Hyde said he had already seen Kjerstad palling around with Jordan Westburg, who made his rookie debut earlier this season.

“Definitely helpful: I think the acclimation process is incredibly hard when you get to the big leagues,” Hyde said. “But to have guys that you kind of grinded it out in the minor leagues and have friends up here already, it’s gonna make things as comfortable as they can possibly be.”

kyle.goon@thebaltimorebanner.com