Patriots cornerback Marcus Jones outruns Jets safety Jordan Whitehead, left, and long snapper...

Patriots cornerback Marcus Jones outruns Jets safety Jordan Whitehead, left, and long snapper Thomas Hennessy to score the winning touchdown during the final seconds of the game at Gillette Stadium in Foxborough, Mass., on Sunday. Credit: EPA-EFE/Shutterstock/CJ Gunther

 ATLANTA

Ya Gotta Grieve.

What else is left right now for these Mets, other than to mourn what might have been and to ponder their crumbling hopes for their first NL East title since 2015.

It’s not officially over. Not yet. But after Sunday’s 5-3 loss completed a stunning three-game sweep by Atlanta at Truist Park that not even the most black-hearted pessimist could have imagined, the Mets’ chances of recovery are almost microscopic.

Collapse, choke, epic failure. Take your pick. The hard truth is the Mets had a 10 1⁄2-game lead atop the NL East on June 1, a seven-game cushion in mid-August and a 2 1⁄2-game edge as recently as nine days ago, when Jacob deGrom imploded against the lowly A’s to start the first domino tumbling out in Oakland.

Coming into this weekend showdown, we were actually talking about the Mets potentially clinching the division by Sunday night. All they needed was one victory, one lousy W, to set themselves up for maybe doing it at Citi Field against the last-place Nationals.

Instead, the Mets delivered the worst-case scenario, getting swept themselves and teeing up Atlanta for a potential fifth straight NL East crown, courtesy of a two-game lead and the tiebreaker by virtue of a 10-9 head-to-head record. One more Atlanta win or one more Mets loss and the Mets are a wild-card team.

They were quick to remind everyone afterward that they wound up only one game worse than Atlanta in the season series, but this is the ugly reality: The Mets lost six of the final seven against the defending world champions and were outscored 51-23 in that span.

“I feel like they just flat-out beat us this weekend,” Pete Alonso said. “They played well. Good for them. Tip your hat.”

Alonso entered the weekend with 40 home runs, third-best in the majors, but didn’t get as much as an extra-base hit while watching Atlanta smack seven homers, including three each by Dansby Swanson and Matt Olson. Both went deep again in Sunday’s finale, with Swanson launching a 409-foot tone-setter as Atlanta’s second batter of the game. Olson iced the Mets with the insurance blast in the sixth inning. Shortly afterward, the sellout crowd of 42,713 at Truist Park momentarily put aside the chop in favor of chants of “Sweep! Sweep!”

“You have to shake it off,” Francisco Lindor said. “It doesn’t feel good. But at the end of the day, you’ve got to focus on what you have in front of you, and that’s the Washington Nationals. Of course we wanted to come here and win a couple of games, but that didn’t happen. Turn the page and move forward.”

But what are the Mets looking forward to? Now they’re likely headed to a wild-card matchup with either the Padres or Phillies, a three-game series at Citi Field that would start Friday. And if they get by that, next up would be the Dodgers.

But what’s the level of trust in the Mets’ Big Three after what we witnessed this weekend? It was total humiliation for the Mets, and Chris Bassitt — the last ace standing — essentially made a cameo appearance Sunday, giving up four runs in 2 2⁄3 innings. The Mets supposedly had lined up their rotation perfectly for this series with deGrom, Max Scherzer and Bassitt in order. But they were more like bowling pins, and once the dust cleared, the Mets’ trio had combined for a 6.91 ERA, allowing 17 hits and six homers in 14 1⁄3 innings.

“Disappointing, obviously,” Bassitt said. “But we’re still playing. It’s not the playoffs. We get to play tomorrow.”

Maybe the Mets were in shock late Sunday night as they dressed and packed up for the flight to New York, because their rationalization for what happened during the previous 72 hours at Truist Park — and the past four months, really — failed to capture the gravity of the situation. They had spent only four days out of first place for the entire season, and then, on the brink of a possible clincher, basically lost the race to Atlanta in Game No. 159.

There’s no sugar-coating that. With the division at stake, the Mets came up small in the biggest moment of their season as Atlanta did the exact opposite. These games weren’t blowouts, but the gap between the Mets and the defending world champs was always just large enough, by every measure.

“There’s a lot of doubt that can creep in if you let it,” Buck Showalter said. “And our guys are not going to. I’ve got a long memory, they do. We know what they’re capable of — it just wasn’t there the last three days. But our guys have answered a lot of challenges and will again. They’re going to get a chance to roll the dice in October regardless.”

Probably as a wild card. Hard to believe.