ATLANTA — Mickey Callaway never saw the iceberg.

The double-down decision on the path to destruction by Callaway made little sense, and his Mets paid the price.

This loss was on the manager, make no mistake.

The Mets could have had one of those momentum-swinging wins Wednesday night over the Braves at SunTrust Park on the day they placed their best hitter, Jeff McNeil, on the injured list with a strained left hamstring.

Then, in the seventh inning, with Callaway totally over-thinking the situation, he yanked lefty Steven Matz, who had retired 14 straight and was on cruise control, allowing only two hits and having thrown only 79 pitches.

Matz had produced as many hits as he gave up over six innings.

The Mets had taken a 2-1 lead in the top of the seventh on J.D. Davis’ two-out, two-run single to center that scored Matz and Amed Rosario.

Then Matz was out.

Callaway went to Seth Lugo, his best reliever, sure, but it was only the seventh inning and even if Lugo had navigated two clean innings, who was going to close?

Unreliable Edwin Diaz? Justin Wilson?

The risk-reward was most dangerous, and it all blew up in Callaway’s face as the Braves scored five times in the seventh to come away with the 6-4 victory. Lugo allowed all five runs on five hits in one-third of an inning.

Sometimes baseball happens. Sometimes the best reliever gets hit.

The Mets scored twice in the ninth to make it an even more painful defeat.

If the Mets miss the playoffs, they can point to this loss as the bone-crushing defeat because they were about to overcome so much on this hot night in Atlanta.

This was the kind of loss that gets managers fired. Afterward, Callaway did not second-guess himself one iota.

“I’ll make that move 100 times out of 100, that’s the right move in my mind,’’ Callaway said.

Whatever happened to watching a starting pitcher mow down the opposition and at least get the chance to get through the seventh?

If Callaway is making that move 100 times out of 100 under those same circumstances, he’d be wrong 100 times.

Matz was pitching a masterpiece. He was in complete control, the pitcher the Mets want to see mature was maturing before their eyes, and yet he was taken out of the game, not even given the chance to start the seventh inning.

Get through the seventh and then go to Lugo. But at least give Matz the chance to keep rolling, maybe even through the ninth.

Asked about the risk-reward of hoping for three innings of clean bullpen work against the first-place Braves, Callaway answered, “Lugo is our best reliever, he’s been our best pitcher overall lately, so the reward is he puts up two zeroes, you win the game.’’

Maybe, but there still would have been the ninth inning to navigate against Ronald Acuna Jr. & Co.

The reward of getting Matz over the hump would be nice. Bullpen baseball is much too much these days, and the Braves nearly blew it in the ninth with their own bullpen shenanigans.

“The plan was to go two innings with Lugo and see who was coming up in the ninth,’’ Callaway said.

Perhaps that is a viable option on a night Matz is not rolling. The game should dictate the move, not the move dictate the game.

That is how you turn an inspiring victory into a terrible loss on a full-moon night.

Matz said he could not remember batting for himself that late and then getting pulled. He certainly has never batted for himself in the seventh inning, retired 14 straight and gotten pulled.

You retire 14 in a row and you are rolling, you have to think you are getting the chance for at least three more outs, right?

“I was feeling good and my command was starting to come together,’’ Matz said.

Before the game, general manager Brodie Van Wagenen said of losing McNeil, “It’s never easy to lose one of your core players.’’

It’s never easy to lose a game that looked like it was going to be a special victory.

This was a night of multiple contributions wasted because of a fateful pitching change by Callaway, a most destructive loss and decision.