PHILADELPHIA — If Saturday served as a showcase of two underperforming Mets pitchers, consider nobody interested.

Sean Manaea was very hittable over his short start, and Kodai Senga behind him didn’t exactly inspire confidence.

Both pitchers are available heading to the trade deadline. Proceed at your own risk if you are a team needing a back-of-the-rotation arm. Maybe better yet: Don’t proceed.

The Mets’ uninspiring afternoon — with the game’s start time moved up an hour because of weather concerns — ended with a 6-1 loss to the Phillies at Citizens Bank Park.

The game unfortunately resumed following a 48-minute rain delay in the seventh inning.

Sean Manaea reacts after allowing a home run during the Mets’ July 18 loss. Imagn Images

Manaea and Senga combined to allow all six runs before the rain delay and didn’t receive more than a morsel of support from the lineup, which produced only three hits.

The Mets fell 17 games below .500 to match their season worst.

The Mets already traded one struggling pitcher, sending David Peterson to the Cubs last month for first baseman Cole Mathis, but that Manaea and Senga are still owed significant dollars may leave the Mets stuck with them.

Manaea is just beyond the halfway point of a three-year, $75 million contract.

Senga, who owns an 8.85 ERA, is still owed roughly $20 million through next season.

Teams interested in starting pitching can pursue Freddy Peralta, another underperformer, albeit one who is earning only $8 million this season and is headed toward free agency.

Manaea, who owns a 4.74 ERA, surrendered four earned runs on seven hits and two walks with seven strikeouts over 4 ²/₃ innings.

It was the third time in his past five starts that he failed to pitch beyond five innings.

Interim manager Andy Green cited the uncomfortable, humid conditions, but Manaea offered no excuses.

Kodai Senga throws a pitch during the Mets’ July 18 loss to the Phillies. Imagn Images

“It was hot, it was muggy, it was all those things,” Manaea said. “But at the end of the day I have just got to go out there and perform. We’re all performing in the same thing.”

Over 1 ¹/₃ innings, Senga allowed six base runners — three hits and three walks — with two earned runs.

Any thoughts that he can thrive as a reliever have dissipated with two shaky appearances in his last three. Senga was bounced from the starting rotation last month.

Kyle Schwarber hits a home run during the Phillies’ July 18 win against the Mets. IMAGN IMAGES via Reuters Connect

On this day, the right-hander hit 99 mph with his fastball, but that didn’t translate into success.

“His stuff is good,” Green said. “There are better outcomes needed, and he’s aware of that. He wants that and we want that from him. But when you watch his stuff come out of his hand, it’s really good.”

Kyle Schwarber continued his rampage against the Mets with a two-run homer against Manaea in the first inning that produced the game’s first scoring.

Schwarber — who had a three-homer game during the Mets visit last month — leads MLB with 33 homers.

Tyrone Taylor’s second-inning blast pulled the Mets to within 2-1.

The homer was the seventh this season for Taylor, who continues to produce against left-handed pitching — he began the day with a respectable .741 OPS against lefties.

Trea Turner cleared the left field fence leading off the fifth against Manaea, widening the Mets deficit to 3-1.

Turner jumped on a sinker that caught too much of the plate and launched it for his 12th homer this season.

Francisco Alvarez’s two-base throwing error on an errant pickoff attempt at first base helped the Phillies take a 4-1 lead on Alec Bohm’s RBI single later in the inning.

Manaea walked Schwarber after Turner’s homer, setting up the run.

Senga left an 0-2 forkball over the plate in the sixth that Bryce Harper smacked for a two-run single that gave the Phillies a 6-1 lead.

Senga allowed a leadoff triple to Bryson Stott in the frame before walking Turner and Schwarber to load the bases.

The Mets’ misery included three errors, one of which Francisco Lindor committed on a throw, continuing a season of defensive lapses for the perennial Gold Glove contender at shortstop.

“It’s not to the level I expect myself and not to the level that people expect us here,” Lindor said of his defense. “For me defense is the most important thing, and it’s been not good at all.”