We aren’t supposed to root around here. Them’s the rules. That’s the law. “No cheering in the press box,” the man said a long, long time ago, and honestly that’s mostly true. We all have our rooting interests, those of us who wear a media lanyard. Mostly those interests look like this:

2A. No extra innings.

Saturday, that changed.

Saturday, this reporter decided to be an unambiguous homer.

Saturday, I rooted for the New York City Football Club to beat the Portland Timbers in the MLS Cup at Providence Park in Portland, Ore., because, as Kay Adams Corleone once told Michael (under admittedly different circumstances):

“THIS MUST ALL END!!!!!”

And by “this” I mean the nearly decade-long drought of championship teams in New York City. The Giants beat the Patriots one day, and the next thing you know we’re all 10 years older, 20 pounds heavier, three shades grayer and the kids’ music is all too damned loud.

NYCFC play in The Bronx. They went 14-11-9. That was good for 51 points. It was good for fourth place in the Eastern Conference. They beat Atlanta United, the New England Revolution and the Philadelphia Union in the playoffs. They are coached by Ronny Deila.

And those are all of the six things I know about NYCFC.

(FULL DISCLOSURE: I had to look up Ronny Deila.)

I admit: I am a fair-weather fan. I come to this moment with intentions somewhat pure. (After watching two seasons of “Ted Lasso,” soccer finally clicked with me. I really do watch stretches of games — mostly Premiership games — which I have never before done.)

But I also come with selfish intent:

We need a New York City champion. In any professional sport. We need to change the conversation around here, the negativity. This is a city in which even sweet stories like last year’s Knicks and last year’s Islanders quickly can become brutal stories, like this year’s Knicks and this year’s Islanders. Maybe the Rangers can keep this up. Maybe Kyrie will come back to the Nets some time this winter. Are you betting on either?

But for one Saturday in December, we had NYCFC. That is all we have. And as a sporting citizen of this city, there was no other way to root. There is no other outcome to want. (Unless you are a diehard Red Bulls fan. Then you get a pass.)

Naturally, I most wanted this to happen for the fans of NYCFC who have supported this team since its inception. But Saturday, we were all NYCFC. Even those of us who are — full, absolute disclosure here — ultimate bandwagon jumpers.

(I didn’t deserve a true fan’s reveling of Saturday’s dance with glory, and I proved it by spending most of the game elsewhere tending to the important business of watching the St. Bonaventure-Connecticut basketball game. I am nothing if not transparent.)

But I followed along. And so I cheered a little cheer for our city when I saw the final score, when I saw NYCFC had beaten Portland on penalty kicks. Our long civic nightmare is over, at last. Viva NYCFC! May one of your brethren (or sister’n; we’ll include the Liberty, too) in New York professional sports join you sometime in the next decade or two!

The Baseball Hall of Fame will add Gil Hodges and Buck O’Neil to its roster of immortals on the same day, and there is no finer way to class up the joint than that. A long, long time coming for two deserving men.

There are some games this year in which I suspect the first thing Tom Thibodeau tells the Knicks at halftime is: “Gentleman, allow me to clear something up: you are, in fact, allowed to guard your man.”

I still have fond memories of Dylan McDermott as Bobby Donnell in “The Practice,” so it is delicious to see him in a role that couldn’t possible be more 180 degrees in the different direction than as mob boss Richard Wheatley in “Law & Order: Organized Crime.”

I know a lot of you have been reading (thank you!) and occasionally disagreeing with our list of Top 75 Knicks of all time. This Wednesday, at 5:30 p.m., I’ll be discussing the project online with Post Sports+ subscribers. Hope to see (and hear from) you there!

Kevin Bryant: Just imagine what Dave DeBusschere’s numbers would’ve been if his corner jumper had been worth the three points it is now.

Vac: Jerry Lucas, too. He was just about automatic anywhere out to 25 feet.

Mark Dantonio: If the Mets hire Buck Showalter, will his first act as manager be to hire George Costanza to oversee the uniforms? Cotton breathes, you know.

Vac: That also would be boffo news for the Ramada Inn in Milwaukee.

@knishboy: It’s been five long years since Eli and the New York Giants got trounced 38-13 in the wild-card game at Green Bay. Daniel Jones is 12-26 as a starter, when healthy. How many more years of the-season’s-over-by-December do we have to endure?

@MikeVacc: In tone and in sentiment that is exactly the right update from the sign attached to the plane that flew over Giants Stadium back in ’78.

Esther Cimitile: As a longtime Beatles fan (saw them at Shea), I thoroughly enjoyed your column “Let It Free.” What a great analogy, you’re right, a fan is a fan. You might want to tune in to Q-104.3 radio on Sunday mornings at 8 a.m. when they do “Breakfast with The Beatles.” The DJ, Ken Dashow, also tells stories and trivia about them. It’s fun.

Vac: It is a must-listen for all of us Beatles-philes. No doubt.

Warming up for my annual Christmas Carols column (coming in next Sunday’s Post) and still touched by the inspiration of “Get Back,” a very special look at the Giants. Maestro, please:

Joe Judge was a man
Beloved by his owner
But he knew it couldn’t last
Joe Judge took his team
To Tucson, Arizona
Then a California thrash
Get whacked! Get wracked!
Whacked all S-S-Sunday long …
Get smacked! Get sacked!
Whacked all S-S-Sunday long …