Zack Wheeler of the Mets pitches during the seventh inning...

Zack Wheeler of the Mets pitches during the seventh inning against the Marlins at Citi Field on Sept. 26. Credit: Jim McIsaac

SAN DIEGO — Steve Cohen one day might be the Mets’ savior, the multibillionaire hedge-fund boss who bankrolls a baseball-operations department that behaves like a big-market team.

But that day won’t come this week, one of the busiest of the baseball offseason.

For now, it is “business as usual,” Brodie Van Wagenen said Monday, the first day of the winter meetings at the Manchester Grand Hyatt San Diego. That was the general manager’s answer when he specifically was asked if Cohen’s increased investment in the team will affect the Mets’ offseason budget, which includes limited wiggle room — about $14 million — before they reach the luxury-tax threshold.

Van Wagenen declined to comment on all matters regarding Cohen, who is negotiating a purchase of a majority stake of the Mets from the Wilpons.

And so the Mets’ business this week revolves not around an ownership change but around pitching help. That is true for the bullpen, sure, but also for the rotation. The Mets have a vacancy after Zack Wheeler signed a five-year, $118 million deal with the Phillies that became official Monday.

The Mets didn’t think Wheeler was worth that kind of money, Van Wagenen said.

“The value for what we thought the investment [was] didn’t line up,” he said. “The projections that we had for Zack both short-term and long-term didn’t quite match up to the market he was able to enjoy.”

Philadelphia disagreed. Manager Joe Girardi, who was a candidate for the Mets’ job, said working with pitching coach Bryan Price and catcher J.T. Realmuto (a Mets trade target a year ago) will help Wheeler.

“You’re going to have a 1 and a 1A with him and [Aaron] Nola,” Girardi said. “When you look at what he’s done the last few years and really throughout his career, he’s continued to get better and better. This is a power guy with four pitches where I think he’s just starting to reach his potential. There is more in the tank there. This guy can be more dominant than he’s been.”

As far as Van Wagenen is concerned, the Mets already have replaced Wheeler — with Marcus Stroman in July. That leaves them looking for someone to slot into the No. 5 spot previously occupied by Jason Vargas (whom they traded in July).

That sort of pitcher comes at a much cheaper cost than the Gerrit Coles or the Wheelers or even the Kyle Gibsons. Don’t expect any expensive surprises.

Van Wagenen’s description of his ideal back-end starter seemed to be of a front-of-the-rotation starter: someone who can reliably pitch once every five games, go deep into games and “have elite performance.”

“That’s kind of what we’re looking for,” Van Wagenen said. “Whether or not we can find that in the marketplace in fifth starters, we obviously have to see how that plays out.

“We have a lot of our quote-unquote needs already filled. It’s a matter of how we can create upgrades, whether it’s in terms of depth or whether it’s in terms of higher impact . . . We always have to try to be conscious of what resources are available.”

Notes & quotes: Yoenis Cespedes’ running and baseball activities progression is going well, Van Wagenen said. But he still wouldn’t say whether the Mets expect him to play in 2020 . . . . Girardi on Carlos Beltran, his former Yankees player, as a manager: “He was a very smart player, and now he can share the knowledge he has with the players that he’s going to manage. Carlos was always well respected, well received, and I know he will be there as well.” . . . Van Wagenen said he expects Jake Marisnick, acquired last week via trade with the Astros, to play centerfield “more against lefthanded pitching and be a nice complement to the rest of our guys out there.” . . . After adding Ali Sanchez to the 40-man roster last month, the Mets are comfortable with their catching depth . . . Bench coach Hensley Meulens said Robinson Cano used to be his bat boy when he played winter ball in the Dominican Republic with Cano’s father, Jose Cano.