WASHINGTON — If you are a Mets fan who has wandered here, in the middle of the Yankees section of the sports page, then I applaud you for caring about the other team in town, and I warn you that the next sentence might make you physically ill. So consider yourself warned.

But this Yankees-Nationals series sure feels like a preview of the 2018 World Series.

(Hey … I DID warn you!)

If you are a Yankees fan, of course, the only part of that sentence that really matters to you is the part about the Yanks being in the World Series, and it probably makes you happy, but no more so than anything else that happens during the course of a regular day.

Like Tuesday, for instance. Right around noon the news broke that Clint Frazier was going to be recalled from Scranton/Wilkes-Barre, and the glee that abounded in Yankees-fan circles was tangible.

It doesn’t seem to matter that, when you take a hard look at Frazier’s 39-game cameo in 2017, he was a less-than average player (a .231 average, a .715 OPS, an OPS+ of 83). If Gleyber Torres was the holy grail of Yankees acquisitions two years ago then Frazier was a nose behind that. Yankees fans love him. And now they have him again. And Frazier looked like he’d just cashed a winning exacta ticket.

“I can’t wait to get started,” he said, “and join the fun.”

Also Tuesday? The Nationals jumped to a 3-0 lead in a game that started even though anyone with a smart phone could admire the bright colors on Weather.com that were all but choking the District — and bright colors are not a good thing to see when you want to play nine innings.

Turns out, they only played 5 ¹/₂. Turns out they tied the game in the fifth, two outs shy of when they would’ve fallen on the wrong end of a shortened game, and they did that because Tyler Austin — snagged in an 0-for-23 slump heading in — knotted the game at 3 with a sac fly after earlier pushing the Yanks back in the game with a long two-run homer off Gio Gonzalez.

They’ll finish the game Wednesday, assuming the bright colors that are still looming go away. And the way the Yankees are going, all that means is an opportunity to win a couple of games on the same day, which is the one thing they haven’t yet done this year.

But back to the original thought …

(And, since we dragged Mets fans into this once already, it does beg the question whether a Yankees-Nationals World Series would be a) just as bad or b) far worse than the 2009 Series Mets fans had to endure when it was the Yankees and the Phillies at a time when the Phils were like Darth Vader to Mets fans. What say you, brave Mets fan who has made it to this, the 12th paragraph?)

The Yankees are clearly the best team in baseball right now. But the Nats entered this series having recovered nicely from an early slog that found them sitting at 11-16 not long ago before recovering nicely and rattling off 13 wins in 15 games. They get a well-pitched game every night, they actually have a reliable bullpen this year and they still haven’t played a game with their full complement of offensive weapons.

The Braves are out to a hot start. The Phillies are playing well. The Mets are starting to show signs that maybe they can break free from the protracted funk that followed a 12-2 start. But the NL East still belongs to the Nats until proven otherwise, and there isn’t another team in the NL that ought to scare the Nats right now.

So, yes: this could well be the final two left standing in late October, which would be a nice renewal of a New York-DC rivalry that has only briefly been visited by the Mets and really has its roots in the Stanley Cup playoffs (though not for a few years) and, of course, by some classic old Giants-Redskins battles (though not for a few decades).

Lot of ballgames between here and there, of course. But on a rainy day, what else do you have but your dreams and your imagination?