NEW YORK -- The Phillies clinched a postseason berth Friday with their 12-2 win over the Mets, a rare clunker from the home team at Citi Field that saw David Peterson allow five runs (four earned), Pete Alonso strike out twice with multiple men on base and the Mets, for once, fail to dig some magic out of their pockets.

The Phillies are likely to enjoy a more robust celebration in the coming days, when they inevitably sew up the National League East. And in Queens, that’s not a problem. Although the Mets created a few inflection points during the second half of the season when it seemed like they could plausibly challenge for the division, they never managed to make it all that close.

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Instead, an NL Wild Card berth is their goal. And in that department, they’re doing just fine. Their loss to the Phillies hardly damaged them at all in the Wild Card race, because the Braves also lost to the Marlins. As such, the Mets maintained a two-game lead over Atlanta with eight to play -- including three head-to-head games next week in Georgia.

“It’s going to continue to be a rollercoaster,” president of baseball operations David Stearns said before the game. “There are never smooth paths, smooth sailings, whether it’s now or into October. There are really high highs, and there are heartbreaks as well. And we’re at the point in the season where the emotions are heightened in both directions, and that’s a really good thing.”

This time of year can also be instructive. Of note on Friday:

Southpaw struggles
For a brief moment earlier this year, David Peterson held the distinction of having the largest gap among full-time Major League starters between his expected ERA and actual ERA. That disparity has since slimmed, due in part to the four earned runs Peterson allowed over 3 2/3 innings to the Phillies.

As it turns out, facing a lineup as potent as the Phillies for the second time in a week is difficult. Although Peterson was sharp in the first inning, Philadelphia went 6-for-9 against him its second time through the order. Partially as a result of that, manager Carlos Mendoza pulled Peterson after just 64 pitches.

“Surprised,” Peterson said of his reaction. “But it was still a close game at that point. He wanted to make a move, and that was his decision. All good, and we’re on to the next one.”

Troubling trend
Mendoza’s move was for Adam Ottavino, who entered in the fourth inning of what was still a two-run game -- a leverage spot, despite it coming early in the night.

Ottavino immediately allowed a single to Trea Turner, intentionally walked Bryce Harper, then served up a three-run homer to Alec Bohm to turn the game into a blowout.

Though those were the first runs Ottavino had allowed in September, Friday marked the third consecutive outing in which he put multiple men on base. Ottavino’s season ERA is up to 4.70, he has allowed runs in four of his past 11 appearances and his strikeout rate has decreased markedly in the second half of the season. All of which raises the question: Can Ottavino, a well-liked veteran and trusted team leader, remain an option in crucial spots?

“He’s getting ahead but not finishing hitters when he needs to,” Mendoza said.

Designated (not) hitter
When J.D. Martinez flied out to end the eighth inning, he deepened his career-worst slump to 0-for-31, the longest by a Met this season. To put things in perspective, Martinez is one hitless game away from matching the longest streak by any player in the Majors. (That belongs to Martín Maldonado, a catcher so unproductive that the White Sox -- who have the worst record in baseball -- released him two months ago.)

“It’s been tough,” Mendoza said. “It’s been hard for him. He’s in the middle of a rough stretch here.”

Martinez, 37, continues to take daily batting practice with his cell phone mounted on a tripod outside the cage, filming every one of his swings. Yet his results are worsening. Last week in Philadelphia, Martinez endured a particularly frustrating stretch that saw him fly out to the warning track (or beyond) three times in the span of four at-bats. This week, his outs have been softer.

Mendoza has already dropped Martinez, his regular cleanup hitter early in the season, to sixth in the lineup. Earlier this week, the manager benched Martinez against a left-handed pitcher -- something that once would have been unthinkable. For about a decade, Martinez has been one of the game’s top sluggers against left-handed pitchers. If he can’t rediscover some of that magic, Martinez could see his role shrink even more into October.