Marcus Stroman was acquired by the Mets for big games down the stretch.

His New York toughness was supposed to be a plus at Citi Field.

The Mets are still waiting for any of that to happen. When they’ve needed him most, he has not delivered.

It simply could not have gone worse for Stroman and the Mets on Saturday night at Citi Field, as Stroman was battered by the Phillies over four innings and the Mets lost a critical game in their uphill battle to capture the second wild card, dropping a 5-0 decision to the Phillies.

Stroman surrendered a second-deck home run to the first batter of the night, Cesar Hernandez, and was in trouble throughout his short stint on the mound.

This was the fourth start at home for the Medford native, and he has yet to sparkle, as he dropped to 1-2 with the Mets with a 5.05 ERA, a thorn in the rotation.

The Phillies could have knocked him out much earlier but left the bases loaded in the first inning and two runners on in the second. They finally broke through in the fourth when they wisely shortened their big launch-angle swings and went for constant contact.

Left fielder J.D. Davis didn’t help matters when he tried to catch Scott Kingery’s easy fly ball with one hand and dropped the ball for an error to start the fourth.

The floodgates soon opened.

Stroman gave up four hits in the inning including Corey Dickerson’s two-run double. Hernandez may have had the biggest hit of the night when the Phillies, after squandering all kinds of scoring opportunities, came through with a run-scoring single to right to score Kingery with the first run of the inning. The Phillies were off and running.

Stroman is not getting ahead of hitters, not getting easy outs and is paying the price.

“We’re missing those early-count outs, he did that so well in Toronto,’’ manager Mickey Callaway explained. “That keeps your pitch count down, so what that does is it not only makes it harder to pitch deep into games, but every batter out there gets to see more and more of his stuff, and sooner or later they are going to get you.’’

It was a bad night all around for the Mets as the Diamondbacks won, beating the Reds, 2-0. Arizona is one of four teams the Mets have to jump with just 21 games to go.

This was the seventh start Stroman has made for the Mets since being acquired in the trade for Anthony Kay and Simeon Woods Richardson on July 28. He owns only one win over that span.

Kay made his major league debut Saturday night with the Blue Jays and allowed two runs over 5 ²/₃ innings in a 5-3 loss to the Rays while striking out eight.

Woods Richardson, according to scouts, is the young pitcher with the better upside. This is a trade that will have to be watched closely.

Stroman was hit hard, surrendering 10 hits. He has come back home to the Mets, but is still figuring out how to succeed here.

There was no efficiency. Callaway even started Tomas Nido at catcher thinking that would help Stroman keep the ball down.

“The game plan is to always try to make them put the ball in play the first three pitches, that’s pitching 101,’’ Callaway said.

Stroman isn’t doing any of that.

“I’m extremely frustrated and kind of angry,’’ Stroman said.

“I have to stay more through the ball, I look forward to the adversity and getting through this,’’ the right-hander added.

It may be too late for this year.

“I definitely wanted to come out hot here and I haven’t,’’ Stroman said. “I just haven’t been myself here.’’

The Phillies played without Bryce Harper (bruised right hand), and right fielder Adam Haseley made a superb running catch to end the first on Todd Frazier’s two-out drive, saving three runs right off the bat against Drew Smyly.

The Mets are just three games over .500, that is hardly playoff material. This is a series they really needed to sweep to be considered in the thick of the race.

Reality, not opportunity, is knocking at the door.

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