Message is clear: This season’s over

Yes, they were missing Yoenis Cespedes and Curtis Granderson from the lineup, and Michael Conforto is on the disabled list, and you’d like to have your full complement of weapons available when you go head-to-head with the Nats.

But it’s worth remembering the Nats are without two key elements of their best-case blueprint, too, in Adam Eaton and Trea Turner. Moreover, while there was a sense of necessity all around the Mets from the moment they first walked into Nationals Park on Monday, the Nats have yet to play their full Alineup. Danel Murphy sat Monday night except for a late pinch-hit appearance. Tuesday, Ryan Zimmerman, Anthony Rendon and Matt Wieters were given full days off.

And the Nationals still went 2-for-2 against the Mets. They’re the Mets. “We have to make pitches and make plays,” said Seth Lugo, who started well, but wound up surrendering six earned runs. “Right now it’s been a struggle to do both.”

It wasn’t against the Giants, or the Marlins, or the Phillies, the three teams the Mets faced leading into this series, against whom they went 7-2, allowing them to build at least a puff of momentum heading in. If there is progress to be found this season, that’s it: the Mets have learned to play better against teams they should beat. If they had done that more in the season’s first two months, when the schedule was loaded with patsies, maybe they wouldn’t have buried themselves so deeply.

But they didn’t do that. And they’re still underwater. Every time they inch within sight of sea level — they were four games under .500 entering Sunday’s game — they slip and fall back into the chasm. They’re seven under now, and when you’re that far south of sea level you barely earn the right to talk about being mediocre, let alone good.

The Mets aren’t very good. It has been three-plus months now, and the evidence is as clear as it has been all year. The National League is still so lousy with dreadful teams that there are plenty the Mets still belong with. Just not the good teams. Just not against the Dodgers (0-4) and the Diamondbacks (0-3) or even the Brewers (2-5), and certainly not the Nats, who have now won nine of 12 and must feel tempted to see what a full spring-training B team might do against Jacob deGrom Wednesday night, just for kicks and giggles.

The Nats have already made their statement here, and all year: loud, clear, and unmistakable.

And so, too, for that matter, have the Mets.