They are ancient rivals, division cellmates from the beginning, their disdain fueled by equal parts familiarity and proximity, their parks located just 116.5 miles apart, each filled with emotionally charged, balled-fist backers.

Until now, the Mets and Phillies have been only summer foes, strangers in October. But by the end of the week, they could very well become the new Yankees versus Red Sox.

It’s #OMG versus #STFU.

Grimace versus the Phanatic.

The Hot versus The Got.

The Mets may be dreaming now, high off the Milwaukee Miracle, but reality looms in Philadelphia.

The Phillies ain’t the Brewers.

They are a team that exploded out of the gate, and despite a brief July hiccup, cruised to the NL East title and second-best record in baseball, narrowly bested by the Dodgers.

A team artfully put together by renown architect Dave Dombrowski, they are October tested, having been to the World Series two years ago and only failing a return trip last year by losing in seven to Arizona in the NLCS.

They have a lineup of bashers, a strong rotation and an even better bullpen.

They embrace the bright lights and are ring obsessed after being so close the last two years.

Don’t be fooled by the fact the Mets only lost the season series, 7-6.

Three of the Mets wins came against Phillies gas can No. 5 starters and you don’t need fifth starters in October.

“On paper, it’s a complete mismatch,” one NL scout said. “The Mets don’t stand a chance.”

This week, we will learn if magic is real. Let me introduce you to the Phightin’ Phillies:

The Brutes on Broad Street

Built to bash, the Phils throw haymakers from the top of the lineup with lefty hulkster Kyle Schwarber, the antithesis of the trad leadoff hitter.

Once a topic of debate, even the purists can’t complain over clogged bases with the club’s success deploying their first-up spirit animal, The Schwarbomb, who set a major league record with 15 leadoff homers this season, the last one coming Sept. 21 on an 0-1 sinker from Mets lefty Sean Manaea.

In fact, since Schwarber joined the Phils in 2022, they are 83-36 when he homers in a game.

Following a disappointing 2023 campaign, second-up Trea Turner rounded back closer to his MVP form this season, but still performed incredibly streaky.

Sandwiched between Schwarber and superstar Bryce Harper, Turner, with his lethal combination of speed and pop, is a key to navigating this lineup.

Harper hit 30 bombs this season — and that’s with a prolonged power outage from Aug. 10 to Sept. 13 in which he went 30 games without a home run.

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The week off should help a nagging sore elbow and he remains as dangerous as they come, especially in October.

Harper started this group’s postseason magic with a homer through the raindrops off Padres fireball reliever Robert Suarez that sent the Phillies to the World Series two years ago.

But the Phillies trio of right-handed bats of catcher JT Realmuto, outfielder Nick Castellanos and third baseman Alec Bohm could very well be key against the lefty-dominant Mets rotation.

Castellanos will hit cleanup. While he’s vulnerable to the breaking ball away, he’s shown much better patience at the plate.

That will allow the young Bohm — whose best gift is plate coverage — to hit fifth and let Realmuto provide some clutch balance in the lineup in the six hole. Realmuto — one of the best defensive catchers in the game with a gun of an arm — is finally healthy after an injury-plagued season.

The bottom third is the weakest piece of the Phillies lineup.

Second baseman Bryson Stott has struggled after a promising two years, especially against lefties.

He’ll likely sit against the Mets lefties for Edmundo Sosa.

Similarly, the young, long-bearded Brandon Marsh will platoon with Austin Hays, the right-handed bat acquired from Baltimore at the deadline.

The Phils will opt for supreme defense in center field with the light-hitting Johan Rojas.

The rotation

Of all the disastrous pitching decisions by the Mets in recent years, the worst, by far, was giving up on Zack Wheeler, who has blossomed into a true ace.

“He’s become a true horse,” the scout said. “He reminds me of Roy Halladay. He’s big and powerful. He throws his fastball anywhere he wants — inside, outside — and his ball is so heavy it’s like hitting a bowling ball. You can’t barrel it up.”

Wheeler allowed just 139 hits and struck out 224 with an 0.96 whip in 200 innings this season.

Thompson opted to throw young lefty Cristopher Sanchez in Game 2 on Sunday. Sanchez, who has much better splits at home, has blossomed into a promising starter. He’s cranked his velocity up to a consistent 96-97 mph and developed a wicked changeup.

“His fastball and changeup come from the same tunnel,” the scout said. “He really keeps a hitter off balance.”

Veteran Aaron Nola, the unflappable innings eater, will pitch Game 3 in New York.

He’s no stranger to the Mets, who have faced him 28 times in his career. He’s 10-9 with a 3.46.

Hero Pete Alonso has had the most success against him with five home runs.

If there’s a weakness with Nola, it’s his penchant for giving up the long ball. He surrendered 30 on the year in 197 innings.

The pen

This is where the Phillies can be very dangerous, especially with the deadline acquisition of closer Carlos Estevez from the Angels.

They have five legit arms to throw in the back end with All-Star Jeff Hoffman and Orion Kerkering from the right side and wicked-stuff lefties Jose Alvarado and Matt Strahm, another All-Star.

“Outside of maybe the Padres, the Phillies have the best bullpen in baseball,” the scout said. “They just have so many options late in the game. And to boot, their starters can go deep into the game. You know Wheeler is just itching to give it [back to the Mets].”

Red October

What makes the Phillies feel even more formidable is the home-field advantage at Citizens Bank Park, a frenzied place that has quickly become unlike any other in the usually hyped Philly — that includes the Eagles at Lincoln Financial Field.

Alex Rodriguez went wild for the Bank the first time he experienced it two years ago working for Fox in the World Series.

“Philly truly has the 10th man advantage,” he said Friday.

“The noise there,” former Phillies manager Charlie Manuel said, “it feels like an ocean wave swallowing you up.”

Post alum Anthony L. Gargano is a content creator for PHLY of ALLCITY Networks based in Philadelphia