Mets relief pitcher David Peterson against the Phillies on Sunday in...

Mets relief pitcher David Peterson against the Phillies on Sunday in Philadelphia.  Credit: AP Photo/Chris Szagola/Chris Szagola

PHILADELPHIA

The Phillies trotted around the bases at will Saturday night and continued the conga line for two more innings the evening after that in a 6-2 victory over the Mets at Citizens Bank Park.

The Mets, wrapping up this six-game road trip against two beatable teams, did a dance of their own. This one was more like a mediocrity mambo — a three-step that seems to propel them forward when, say, Nolan McLean reverts to previous dominance and back again when Freddy Peralta has the worst start of his career, as he did against the Phillies on Saturday.

The result? Just two wins over two series, a 10-10 record since May 30, a 27-27 record since their 12-game losing streak ended and 34-43 overall.

Back and forth, back and forth, until time eventually runs out and they’re in exactly the same place they began.

“We’ve been having a little bit of a hard time here trying to get some winning streaks,” Carlos Mendoza said Saturday. “But they’re too good, too talented. We’ve got be able to figure this out. We’re going to need them, and when they get going here — and we need them to get going pretty soon.”

Pretty soon is already not soon enough, and a lot of that comes down to what’s happening on the mound.

We certainly saw it Sunday, as David Peterson, making his first start since May 26, imploded in the first 1 1⁄3 innings, allowing five runs (four earned) before settling down.

No matter — in one respect, the damage was done, as he had to be pulled after four innings.

Kyle Schwarber, who hit three homers and drove in six runs on Saturday night, hit a three-run shot off Peterson. Bryce Harper, who hit for the cycle on Saturday, fell a triple short of the cycle on Sunday.

While the Mets have suffered ills of all ilk, their starting pitching has been a liability — one marked by internal inconsistency and an apparent inability to get rotational pieces “right” at the same time.

So while you can find solace in McLean’s performance last week or Sean Manaea’s ability to grit out 5 1⁄3 innings in Thursday’s win, you also have to deal with the fact that whenever they seem to plug up one hole, another one opens.

Clay Holmes is hurt. Christian Scott is hurt. And Peralta, who gave up a career-high 10 earned runs Saturday, has an 8.14 ERA in his last four starts. Downtrodden, he was embraced by Francisco Alvarez by his locker after the appearance.

“I’m not worried about it,” he said. “Of course I don’t feel good right now, but I’m not worried about it.”

Mendoza espoused similar (forced) optimism.

They’ll fix Peralta “the same way we did it with Sean, the same way we did it with Nolan,” he said. “He’s too good of a pitcher ... He’s going through a bit of a rough stretch here, but if somebody is able to bounce back after bad outings, it’s a guy like Freddy. He’s a competitor, a guy who’s going to come back the next day and look for ways to get better and improve.”

But all these improvement projects aren’t cutting it anymore.

Going into Sunday’s series finale, the starters’ 4.69 ERA was 27th in baseball; those pitchers strike out plenty of batters but issue a ton of free passes, too, with a strikeout-to-walk ratio of 2.28, or 23rd in MLB.

They throw the most pitches per inning in baseball — an average of 17.31 — while also clocking less than 4 2⁄3 innings per start (granted, some of that is skewed by the fact that the Mets often have used openers this season, but they’re hardly the only MLB team to rely on the strategy).

While the offense has hardly been stellar and the defense has been well below average, it’s hard to get past the starter problem. That is what might doom their season.

When they face the Cubs on Monday, the Mets will be forced to turn to Kodai Senga, who looked very shaky in his return from the injured list last week. After that, it’s the same tired carousel — hope McLean is good, hope Manaea keeps figuring it out, hope 2025 Peralta comes back from the dead, hope Peterson lives up to his potential.

Hope, hope, hope until too many calendar pages turn and hope is useless. Hope is not a plan.

All of it is a not-so-subtle indictment of David Stearns’ approach to starting pitching. There weren’t exactly a host of tantalizing options in the offseason, but labeling Peralta an “ace” was a mistake; in reality, other than last year, he’s a good No. 2 or very good No. 3. This year, his 4.83 ERA is 60th among qualified starters. There are only 66 qualified starters.

The Mets have needed a true ace for two seasons now, and for two seasons now, they have been stingy about offering the type of contract that would attract an ace.

That’s easy enough to remember when a guy like Zack Wheeler takes the mound, as he did for the Phillies on Sunday. Who can forget then-general manager Brodie Van Wagenen saying the Mets helped Wheeler “parlay two good half-seasons over the last five into $118 million.”

Since those comments, Wheeler has been a three-time All-Star and finished in the top 10 in the Cy Young Award voting four times. Hindsight is 20/20, but Wheeler is a good illustration of what it means to be able to count on someone who can bust losing streaks and create winning ones. Instead, the Mets are relying on best-case scenarios in a season that has shunned best-case anything.

“You trust those guys have done it before,” Mendoza said of his struggling starters. “They’ve had success in this league, especially when they’re healthy ... We continue to go back to who they are, what made them a success before and continue to work for them. It’s not that they forgot how to pitch.”

Sure, but they’re not remembering that quickly enough. It’s ending games (and potentially a season) before they’ve barely begun.

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME