On a night when the Mets needed starting pitcher Noah Syndergaard to be brilliant, he was just plain bad, burying the Mets in a hole they couldn’t escape and making them losers for the fifth straight game.

Yes, the Mets offense finally woke up, and maybe that means something Thursday night when the home team faces a huge gut-check as it tries to avoid being swept for the second straight series. But turning a 10-1 deficit into a 10-7 loss isn’t exactly the kind of moral victory the Mets need.

“We’ve got our ace on the mound and he’s going to do what he does best,” Syndergaard said of Thursday’s starter Jacob deGrom.

The Mets were expecting something similar from Syndergaard. A picture of reliability for much of the season and especially of late, the right-hander didn’t have it against the Cubs. He didn’t have his changeup, didn’t have his slider, and didn’t have his command. The result was an eyesore of an outing in which he allowed nine earned runs in just three innings, starting with a six-run first when the Cubs sent 11 hitters to the plate.

“He just didn’t get into a rhythm and couldn’t get where he wanted to get,” manager Mickey Callaway. “It was just an off-night for him.”

If it was anyone else but Syndergaard, he probably wouldn’t have been allowed to pitch beyond the first. But the Mets sent him back out for more, and by the time the Cubs added two more runs in the second and another pair in the third to take a 10-1 lead, it was time to show some mercy. Syndergaard wound up allowing 10 runs (nine earned) on nine hits, including three home runs. He struck out five.

“They capitalized on every mistake I made,” Syndergaard said. “When it rains it pours. I was disappointed in myself. I had an opportunity to do something big, but I let the team down.”

Syndergaard’s stinker was unexpected. In his previous start against the Indians last Thursday, he had taken a perfect game into the sixth inning before giving up a hit. That night he was working on a two-hit shutout when a long rain delay ended an outing where he had displayed some of his best stuff of the season.

There was no reason to believe he wouldn’t be just as good Wednesday. Over his previous eight starts, Syndergaard had worked at least six innings. He was also 6-1 in his past seven starts at home, dating back to June 9. Yet, he complained of feeling “unathletic” in his previous starts and was hoping to feel more whole against the Cubs.

“You’ve got to grab the ball on the mound and focus on the next pitch,” he said. “But it just wasn’t going my way. The Cubs did what they were supposed to do.”

Syndergaard (9-7, 4.14) didn’t get much help either. An error by shortstop Amed Rosario helped the Cubs in the first inning, when he threw wide of second base trying for a double play. In the second inning, a pop fly down the left-field line was lost in the haze and rain, and fell between Rosario and left fielder J.D. Davis. Though it wasn’t ruled an error, the ball should have been an easy out.

“Stuff like that happens,” Syndergaard said. “You have to have short-term memory.”

Now, the Mets find themselves in a desperate situation. They began this homestand with all kinds of momentum and optimism, certain they were ready to prove they are a real contender for a wild-card berth. But after being swept by the Braves in three games, they now face the possibility of being swept by the Cubs before heading for a three-game series in Philadelphia.

“We’ve already lost the series,” Davis said. “We’ve got to scratch one [win] any way we can.”

DeGrom will start for the Mets on Thursday, hoping to put in a better performance than Syndergaard did Wednesday night.

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