Mets general manager Billy Eppler mentioned this week that there is “runway” until they have to decide if they are buyers or sellers at the trade deadline — and that runway appears ready to close.

Pete Alonso’s tormented face in the eighth inning — caught on camera by SNY — said it all Friday night after David Robertson allowed a go-ahead homer to Patrick Bailey that sank the Mets in a 5-4 loss to the Giants at Citi Field. Alonso’s throwing error earlier in the inning contributed to the meltdown by the Mets, who are now 36-46 and just bad enough to keep losing.

But there is no evident reason to believe manager Buck Showalter will find the magic potion over the next few weeks (sorry, Jose Quintana’s imminent return doesn’t resonate enough) and transform this club into a wild-card contender before the Mets have to decide on potentially overhauling the roster.

Twenty-three games remain before the Aug. 1 trade deadline, and barring something like an 18-5 run, it’s safe to assume July will be the last month in which several members of this roster will wear a Mets uniform.

Playing only a few games above .500 for the next month — which would represent remarkable improvement for a team that went 7-19 in June — won’t cut it.

Steve Cohen may regret that he said, upon buying the team before the 2021 season, that he would be disappointed if the Mets didn’t win a World Series in three to five years. He acknowledged in his press conference on Wednesday the difficulty of accomplishing such a task. But it’s hard to envision, even as the Mets crave elite prospects that would restock their farm system, that Cohen would blow up the entire team and cripple the organization’s chance of competing for perhaps the next two or three years.

Even so, there are few untouchables on this roster (we’ll exclude Edwin Diaz, who is rehabbing from knee surgery). Everybody should be available with the exception of maybe three players. Before we list those untouchables, we’ll name a few who should be available under the right circumstances (other than the obvious candidates on expiring contracts):

Francisco Alvarez: It would have to be a special deal for the Mets to even consider dealing the rookie catcher, but if a team were willing to trade an elite pitching prospect for Alvarez, it might make sense.

The Mets have another highly regarded catching prospect, Kevin Parada, and could probably survive one season with Omar Narvaez as the primary catcher. The opportunity to land a stud pitching prospect might be the only case in which trading Alvarez should be considered.

Brett Baty: There is some thought in the organization that the rookie third baseman’s future will be as a corner outfielder. So the Mets may not necessarily have their third baseman for the next decade in Baty, even if he fulfills his high potential on offense.

Much as with Alvarez, the Mets shouldn’t be in a hurry to trade Baty, but he doesn’t reach untouchable status.

Jeff McNeil: After he won the NL batting title last year, it finally seemed he had arrived as a core player. A half-season into his four-year contract extension, worth $50 million, McNeil — despite two doubles Friday — is floundering and might not garner much of a return in a trade.

Justin Verlander and Max Scherzer: Both pitchers have been disappointments and could be available if they are willing to waive their no-trade clauses and Cohen is willing to eat a significant amount of their contracts. They certainly aren’t untouchables, but the logistics in trading either could be difficult.

And now for those untouchables …

Alonso: He’s probably the Mets’ best asset for a quick infusion of top prospects, but trading Alonso would essentially “wave the white flag,” as one major league talent evaluator said this week, that the team isn’t serious about winning next year.

Drafted and developed in the organization, Alonso can become a free agent after the 2024 season and should remain a focal point for the front office even if the Mets believe they can sign Shohei Ohtani this offseason. Alonso is a face of the franchise.

“I can’t picture him anywhere else,” Michael Conforto, Alonso’s former Mets teammate, said Friday.

Brandon Nimmo: He just signed an eight-year contract worth $162 million in the offseason and has consistently expressed his desire to play his entire career for the Mets. The 30-year-old’s no-trade clause puts him in position to fulfill that goal. Nimmo has become the successor to David Wright as “Mr. Met” and despite a defensive slump, still provides a presence atop the lineup that wouldn’t be easily replaced.

Francisco Lindor: Though he hasn’t lived up to superstar expectations, he is still among the game’s best shortstops and wouldn’t be easily replaced. That point aside, even Cohen isn’t going to absorb enough of the $290 million or so remaining on Lindor’s contract to make a trade worthwhile. It shouldn’t matter. If the Mets are going to compete for a championship in the next few years, they will need Lindor.