Sandy Alderson is the prototype for the modern baseball general manager — Ivy League-educated, deeply analytical and progressive in his approach to new methods, tools and statistics. He drafted Mark McGwire. He mentored Billy Beane. He won a World Series. But he has always been more than a baseball man; he is a lawyer, an educator and an ex-Marine who did a tour of duty in Vietnam. He is the sport’s consummate Renaissance man.

But baseball will be without Alderson for at least the foreseeable future after he announced Tuesday he is stepping down as GM of the New York Mets following a recurrence of cancer. His departure is open-ended, as he pointed to the team’s disappointing season — a win Tuesday night left the Mets at 32-45, in fourth place in the National League East — and said, “If I were to look at it on the merits, I’m not sure coming back is warranted.”

At 70, Alderson was at the time of his departure the oldest GM in the game. The Mets’ front office will be run for now by three of his lieutenants: Omar Minaya and J.P. Ricciardi, both former GMs themselves, and John Ricco, a longtime assistant GM.

“It’s a matter of rearranging priorities, accepting limitations — temporarily, at least,” Alderson said Tuesday in an unscheduled news conference at Citi Field. “My family, as you might imagine, has been tremendously supportive. I have tremendous doctors. And I’m confident this will end up happily. But it’s an adjustment.”

Alderson, a 1965 graduate of Falls Church High School, was hired to be the Mets’ GM in 2010 and steered the franchise to the NL pennant in 2015 and another playoff berth in 2016. But his cancer, the type of which was never specified, was originally diagnosed in the fall of 2015, and though he often spoke optimistically of his recovery in the intervening years, the recurrence was discovered two months ago. He said he has been undergoing chemotherapy and will undergo surgery later this summer, but he informed the Mets’ ownership Sunday of his plans to step down.

“My prognosis is actually good,” he told reporters. “But in the meantime — the chemotherapy [and] the surgery all take their toll.”

Before meeting the media Tuesday, Alderson addressed the Mets’ players, who gave him a standing ovation when he had finished.

The Mets, following a star-crossed and injury-riddled 2017, expected to be contenders again in 2018 under new Manager Mickey Callaway. They started the season with 11 wins in their first 12 games and held first place in the NL East until early May, but they began unraveling amid another rash of injuries that month — then completely collapsed in June, going 5-18 thus far entering Wednesday, with separate losing streaks of eight, seven and four.

“I feel badly that we’ve had the season that we have had to date,” Alderson told reporters. “I feel personally responsible for the results that we’ve had. … It’s been an incredibly difficult situation. And I’m really disappointed with where we are — disappointed to leave Mets fans, basically, in this situation.”

Alderson’s departure comes at a critical juncture for the Mets franchise, with the July 31 trade deadline looming and speculation around the industry that the team will sell off pending free agents such as closer Jeurys Familia and second baseman Asdrubal Cabrera, and perhaps even deal away one of its highly coveted aces, right-handers Jacob DeGrom and Noah Syndergaard. Such moves could go a long way toward rebuilding a farm system widely regarded as one of the worst in the game.

“This is a results business,” chief operating officer Jeff Wilpon, seated next to Alderson at Tuesday’s news conference, told reporters. “We’re well below our expectations, from ownership on down.”

Alderson’s arrival in Queens in 2010 came in the aftermath of the Wilpon family’s embroilment in the Bernie Madoff financial scandal, and the timing was no coincidence: Aside from Alderson’s baseball acumen, the Wilpons were also attracted to his sterling reputation as a leader and his unparalleled résumé — which includes not only his military background but also an undergraduate degree from Dartmouth, a law degree from Harvard, stints running the Oakland Athletics and San Diego Padres, and a seven-year run as Major League Baseball’s executive vice president of baseball operations.

“Coming into this job, obviously, I had heard a lot about Sandy Alderson and the leader he was,” Callaway, the Mets’ rookie manager, told reporters Tuesday. “I experienced all of those things firsthand, and he lived up to all those qualities. . . . He’s a badass Marine. That’s all I can say.”

One of the game’s great minds, Alderson has never stopped thinking of ways to improve the sport, even after leaving the commissioner’s office in 2005. In a discussion about the game’s pace of play, in his office at the Mets’ spring training headquarters in March 2017, he cited behaviorist B.F. Skinner’s theory of “intermittent reward and reinforcement” to argue against a change to the strike zone.

“It’s a dynamic process,” he said then. “There’s no question the game has changed, but the question is how change the pace of the game without altering the nature of the game.”

However long Alderson is out of the game this time, the Mets will adjust and press forward in whatever direction they choose. But baseball will be lesser in his absence.

“None of us writes his or her script,” Alderson told reporters Tuesday. “We deal with circumstances as they arise. And I’m grateful for all the opportunities I’ve had here and in the game, and for whatever opportunities may arise in the future. But this isn’t Disney World, and we have to deal with life as it presents itself. And I’m okay with that.”

Read more: