Grant Hartwig wanted to make the majors as a doctor. Now he might do it as a Mets pitcher.

PORT ST. LUCIE, Fla. — The wildest 48 hours of Grant Hartwig’s life started with him sitting at a desk in his childhood bedroom in Plymouth, Michigan, on a random Friday afternoon less than two years ago. He was doing what basically was homework, steadfast in his pursuit of his long-held goals: medical school and — eventually, hopefully — working as a doctor for a major-league team.

That weekend ended with him on a plane on the way to Port St. Lucie, beginning his out-of-nowhere shot at professional baseball. He hit pause on those academic plans to see what would happen, bringing him to where he is now: in major-league spring training with the Mets and on the brink of the majors . . . as a pitcher.

Hartwig, a 25-year-old righthanded reliever, zoomed across four levels of the minor leagues last year, his first full season, impressing Mets officials with his intellect as much as his physical ability. They view him as a possible option for the bullpen this season.

“He’s got potential,” manager Buck Showalter said, “to be somebody who could impact us.”

And all of this almost never happened.

On the July 2021 day the Mets called seeking to sign him, Hartwig was at his parents’ house taking a practice version of the Medical College Admission Test — the MCAT, sort of like the SAT for med school. It was an endeavor that took hours and required great focus. When the phone rang, he didn’t recognize the number. He ignored it.

That somebody was looking for him for a baseball-related reason didn’t occur to him. He was a lifelong ballplayer, loved the game, always had, but considered himself retired by virtue of graduation.

“I was ready to move on,” Hartwig said. “I was done.”

‘A little bit scared’

In the several years before Hartwig entered his last collegiate season at Miami University of Ohio, he had barely pitched. Tommy John surgery in 2018 — an experience that solidified his desire to become an orthopedic surgeon — and the pandemic in 2020 yielded a series of stops and starts to a statistically unremarkable run.

So when he found himself a fifth-year senior, expecting to fill a reliever/starter hybrid role, he hadn’t talked to any scouts. They were watching, though.

The Mets liked and wanted Hartwig based on the recommendation of at least two people: Chris Heidt, their scout whose seven-state territory includes part of Ohio, and Moises De La Mota, their supervisor for Latin America.

Heidt wound up seeing Hartwig because the Mets had interest in his teammate, Sam Bachman, for the first round of the draft that summer (he went to the Angels with the ninth pick). In Hartwig, he noticed an older pitcher with decent arm strength who threw the ball from a lower, unusual angle. His improvements since the previous fall were obvious.

De La Mota visited Miami as a sort of cross-training assignment. The Mets sent members of their international staff (who watch kids beginning several years before they are eligible to sign at 16) to watch draft prospects in the United States as a way to build and calibrate their evaluation skills. On his first such trip stateside, he expected an educational experience, not to see any talent that stood out.

But then De La Mota got a familiar feeling in his stomach, a signal from his intuition “when players are going to be good,” he said. Hartwig’s slider reminded him of Mets reliever Adam Ottavino, his big body (now listed at 6-5 and 235 pounds) reminiscent of Phil Hughes. And Hartwig was awfully intense on the mound.

“He was pitching like it was the most important game of his life or it was the last game he was going to pitch ever,” De La Mota said in a phone interview from the Dominican Republic. “He gave so much importance to that outing, I was impressed. You don’t see that happen very often.”

Surprised by how strongly he felt after seeing Hartwig pitch just once, De La Mota emphasized to his bosses that this was a guy worth giving a shot. When the draft came and went and no team touched Hartwig, Tommy Tanous — the Mets’ vice president of amateur and international scouting — gave Heidt the OK: Offer him a contract.

Hartwig was aghast — and skeptical — when he eventually called Heidt back and realized the Mets wanted to sign him.

“It was like, holy [expletive], it’s a great opportunity. I’m kind of excited. But also a little bit scared,” said Hartwig, who had just received his degree in microbiology. “I worked five years, tons of stress throughout college, putting in work toward doing premed. It’s hard to walk away from that — from long nights, early mornings, studying all throughout the night, missing things throughout college doing that lifestyle.”

Heidt said: “He at one point told me, ‘I really don’t think I’m going to do this.’ ”

Hartwig had committed so much time and energy and money — hello, undergrad student loan debt — that he wasn’t sure about throwing that away. He’d spent about 400 hours studying for the MCAT, which was two weeks away. Speaking as someone who went back to school in his 30s, Heidt told him that school always would be there as a fallback. Professional baseball wouldn’t.

The Mets offered Hartwig $20,000, which he at first didn’t realize was the maximum signing bonus for an undrafted free agent. They were showing as much interest as they were financially allowed. So Hartwig — who didn’t even have an agent, because why would he? — talked it over with his family, including his mom, Colleen Hartwig, a physician and the initial reason her son wanted to become a doctor.

“She was like, ‘You don’t need any approval from me. I can already tell your mind is made up,’ ” Hartwig recalled. “That was all I needed to hear.”

Heidt said: “He said he needed a couple of days to think about it. It was about 45 minutes later he called and said what the hell, let’s do this.”

Hartwig arrived at the Mets’ minor-league facility by the end of that July 2021 weekend.

‘It’s mind-boggling’

After dabbling in games at the end of the 2021 season, Hartwig entered 2022 with a similar mindset toward pro ball: Eh, may as well see what happens.

During the offseason, he worked as a medical assistant — more for the experience, he said, still looking toward med school, than the money — while training for the season to come. That made the arrival of spring training last year a relief, as he was able to focus on baseball.

The Mets had Hartwig open the season at Low-A St. Lucie, the lowest full-season level of the minors, because, well, they weren’t quite sure what to expect from him.

“It’s hard to be certain what level is the best environment for the player,” said Kevin Howard, the Mets’ director of player development. “So oftentimes you try and err on the conservative side and let the competition tell you if the player belongs at a higher level.”

That proved to be the case with Hartwig, who ascended the minor-league ladder at a rare pace. He earned a promotion to High-A Brooklyn in mid-May, to Double-A Binghamton on July 4 — his Uber had to fight Coney Island hot dog eating contest traffic on the way out — and to Triple-A Syracuse in mid-September.

He seemed to get better as he faced tougher competition, too, striking out 83 batters in 56 2⁄3 innings to go with a 1.75 ERA and 1.09 WHIP.

“It was insane,” Hartwig said. “It was awesome.”

Said Hayden Senger, a Mets minor-league catcher who played with Hartwig in college and in Binghamton: “It’s mind-boggling. It really is.”

And Howard: “Grant quickly proved he deserved to move up by the way he was performing in the games . . . Grant is someone who not only works hard but works smart. His velo and off-speed pitches both improved drastically as the season progressed, which led to his elite performance.”

Hartwig always has been “a smart guy, a little smarter than the rest,” Senger said, the sort of student who studied a lot but did well in class even when he didn’t apply himself. In his new Mets context, that meant a heavy interest in analytics and using that information to sharpen his go-tos: a sinker and a slider.

That has continued into this year with plans to throw his recently improved cutter, which he predicted would be “a staple” against lefthanded batters.

“Grant’s interest and aptitude for analytics is about as high as it gets,” Howard said. “He researched examples of what other pitchers with his similar skill set have done to improve against lefthanded hitters. He decided to develop a cutter so he can have another weapon to get inside on lefthanders and allow his other pitches to play up. He used the feedback from the pitch data to adjust his grips until he was getting the shapes he thought would be most effective.”

Hartwig has tossed a scoreless inning in each of his two Grapefruit League outings, striking out three batters and touching 97 mph with his sinker. The Mets think there are more gains to be made, too.

Yeah, medical school can wait.

“I’m all in,” Hartwig said, “on baseball.”

By Tim Healey

timothy.healey@newsday.com@timbhealey

Tim Healey is the Mets beat writer for Newsday. Born on Long Island and raised in Connecticut, Tim has previously worked for the South Florida Sun Sentinel, the Boston Globe and MLB.com. He is also the author of “Hometown Hardball,” a book about minor league baseball in the northeast.