It must first be acknowledged that Nolan McLean is not by any means a perfect pitcher, nor is he an extremely refined one (yet).

However, his line Thursday — 5 1/3 innings, five runs allowed on five hits and two walks — feels almost nonsensical. McLean entered the night carrying a superb 1.27 ERA, and for the first half of his outing, he looked every bit as dominant as that number suggests.

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McLean opened with authority, stranding a man on second in the first and then striking out the side in the second. Through the first three innings, the Cubs had managed just two baserunners.

But once the order turned over, Chicago began to capitalize.

In the fourth, Seiya Suzuki finally got to McLean, turning on a poorly located changeup for a solo homer. It was one of just five changeups he threw all night. Still, McLean quickly rebounded with a pair of strikeouts to limit the damage, cruising into the fifth with a comfortable 6-1 cushion.

Dansby Swanson’s solo shot in the fifth signaled that the Cubs were starting to time him up. Swanson crushed a middle-in sinker 402 feet to right, cutting the deficit to 6-2. Even so, McLean looked positioned to hand a quality start to the bullpen.

As the bottom of the sixth began, however, it became apparent that McLean was beginning to tire. McLean opened the inning by striking out Nico Hoerner for his eleventh punchout, again leaning on deception in his sequencing. Hoerner took two called strikes right down the middle, one a backdoor sweeper and the other a sinker. Unfortunately, after that, McLean lost his edge.

Ian Happ worked a six-pitch walk without taking the bat off his shoulder, and Moisés Ballesteros followed with a ground-rule double down the line to put two runners in scoring position. Sitting at 82 pitches, it would have been practical to turn the game over to the already warm Ryne Stanek. Skipper Carlos Mendoza instead stuck with his starter, and the decision backfired.

Suzuki stepped up to the plate again, this time hammering a hanging backdoor sweeper into the seats in left for a three-run homer. In a matter of minutes, McLean’s strong outing had unraveled, leaving him with a final line that masked how sharp he had looked for most of the night.

Afterward, McLean didn’t shy away from acknowledging where things went wrong.

“Obviously ended up getting stung a little bit at the end, a couple of solo shots, but try to focus on the positives,” McLean said.

Luckily, the Mets’ bats gave their bullpen the cushion they needed, jumping on Cubs starter Shota Imanaga early and building a lead that the bullpen, which has been much stronger lately, held comfortably. For McLean, that support made all the difference.

“A win’s a win. Just appreciate the offense keeping me in the game,” McLean stated.

Even with the crooked numbers, McLean kept the fire inside him.

“I want to win every game,” he said. “It’s just how I was raised and how I compete. I just like winning.”

That competitive streak, paired with Mendoza’s steady trust, is what continues to make McLean such a central figure in the Mets’ push down the stretch.

“A lot of confidence. You feel good about your chances every time he takes the baseball,” Mendoza said. “The poise…the way he makes adjustments, today it was the cutter. There’s a lot to like.”

McLean certainly showed that adaptability Thursday. He threw 40.4% hard stuff, topping out at 97.4 mph on his fastball while averaging 95.1. His mix generated 13 swinging strikes, including seven on the curveball and three on the sweeper. He found ways to keep the Cubs off balance, especially with the cutter. Clearly, the changeup wasn’t exactly “on” on Thursday, but he was able to lean on his other offerings to keep hitters guessing, at least until the sixth.

Currently, if the Mets do make the playoffs as the No. 6 seed, McLean would be slotted to start Game 1 of the Wild Card Series on standard four days rest. And although he doesn’t boast the experience or track record that potential competitors like Blake Snell or Yoshinobu Yamamoto do, his 2.06 ERA and ridiculous spin rate on his curveball make him more than capable of keeping a potent lineup like the Dodgers in check.

In a short series, McLean has the right tools to be a Game 1 starter now — and hopefully for many more Game 1’s to come.