WEST PALM BEACH, Fla. — Tucked into the Mets’ expensive, high-profile offseason was a cheaper, less sexy transaction to acquire a pitcher they like — a guy who has the contract to prove exactly that.

Justin Hagenman, a 28-year-old righthander, has never pitched in the major leagues. The Mets signed him to a major-league deal anyway.

That unusual but not unprecedented move stemmed from a variety of factors, including his recent performance and perceived potential, which led the Mets to one conclusion: He is worth it.

So now Hagenman is on the 40-man roster, ticketed for Triple-A Syracuse to begin the season, a noteworthy piece of depth whenever the Mets next need a multi-inning reliever or spot starter.

“He’s going to be a guy that we’re going to be looking at closely,” manager Carlos Mendoza said.

Pitching coach Jeremy Hefner said: “There’s a lot to like there.”

Roster flexibility was part of why the Mets wanted him. Because Hagenman has never been on a 40-man roster before, the team is free to shuttle him between the minors and majors, an option they value — and a dynamic they could have for years. While they wait for prospects Brandon Sproat and Blade Tidwell to present themselves as midseason options, Hagenman is a near-term alternative.

And then there is the actual pitching. The Mets like Hagenman because he doesn’t walk many batters, has an intriguing repertoire and impressed to a degree in his first real taste of being a starting pitcher last season. And given what the Mets’ pitching department has accomplished in the recent past to help hurlers maximize their talents, they think all of the above can be improved upon.

Hefner referenced helping Hagenman “get back to his roots a little bit” in terms of pitch mix. Specifically, Hagenman noted a return to his original slider after an experiment that didn’t work out last season but wanting to keep a new cutter.

“They like my ability. They think I can make starts at the big-league level and get people out a couple times. It lines up with how I see myself,” said Hagenman, who pitched in the minors for the Dodgers and Red Sox over the previous seven years. “I can attack hitters multiple ways, get people out a couple of times through the order. I don’t need a whole overhaul. Obviously, I’m trying to get better, do everything I can do. But I don’t need to change everything I do. They kind of like what I do already.”

Hefner said: “I like his compete. Quick to the plate, holds runners well, doesn’t walk a ton of guys, has the ability to miss bats.”

Hagenman’s aggression on the mound is something the rest of the staff could learn from. Last year, the Mets walked 9.6% of batters, the third-highest rate in the majors (and the highest of any playoff team). Hagenman issued walks at a 7.8% clip, which would rank in the bottom third among teams.

“I’m always, always on the attack,” he said. “What I’m trying to do is make the hitter think about swinging at every pitch. Make the hitter always be ready to go, not give him anything free. Obviously, if you’re pitching on the defensive, it’s a lot harder and they can get more comfortable in the box. So just always, always being on the attack.”

After three seasons at Penn State, Hagenman turned pro in 2018, when the Dodgers selected him in the 23rd round of the draft. From there, he climbed through Los Angeles’ farm system at a normal pace, competing mostly as a reliever, reaching Triple-A in 2022.

In July 2023, the Dodgers shipped him (and fellow righthander Nick Robertson) to the Red Sox to reacquire Enrique Hernandez, their longtime utilityman and perennial October hero. In his first and only full season with Boston, Hagenman served as something of a swingman for the Triple-A club, making 15 starts and 13 relief appearances, posting a 4.91 ERA in a personal-high 91 2/3 innings.

And then he hit free agency — minor-league free agency.

“I didn’t really know what to expect,” Hagenman said. “There were a couple teams that reached out with interest pretty early on, the Mets being one of them . . . Talking to the guys, talking to the staff, talking to everyone I could talk to within the building — it seemed right. It fit.”

Notes & quotes: Tylor Megill’s bid to win a rotation spot continued in the Mets’ 7-4 loss to the Astros on Tuesday. He struck out five in four scoreless innings against a representative Houston lineup that featured Jose Altuve, Isaac Paredes and Yordan Alvarez at the top. “He got ahead and stayed on the attack. That was really good to see,” Mendoza said. “That’s what it’s going to take with him: attacking hitters and being around the zone” . . . Utility infielder candidate Donovan Walton hit a grand slam . . . Luisangel Acuna went 2-for-3, raising his Grapefruit League average to .261 (.596 OPS).