Mets' Brandon Nimmo celebrates with teammates after his seventh-inning home...

Mets' Brandon Nimmo celebrates with teammates after his seventh-inning home run against the Marlins at Marlins Park on Sept. 20, 2017 in Miami. Credit: Getty Images / Joe Skipper

Less than 15 minutes had gone by since a meaningless September blowout loss had passed into the history books, never to be thought of again. For the Mets, the defeat represented the final act of a nine-game, three-city road trip just before a day off at the end of a long, fruitless season.

Nobody would have been blamed for sprinting toward the bus that would take them to the waiting charter back to New York.

Yet Brandon Nimmo hunched over a computer screen on Wednesday afternoon, still dressed in a dirty uniform, flanked by hitting coach Kevin Long, refusing to move on until he had his answer. He had to know. He always has to know.

The owner of one of the sharpest batting eyes in baseball needed visual proof that the pitch he laid off, the pitch he believed was ball four, the pitch that was called a strike and altered the course of his ninth inning at-bat, was indeed, as the umpire decided, actually a strike.

“I’ll just say this,” Nimmo said a few days earlier when asked about this habit. “There’s very few times that I’ve gone back and it’s been there [in the strike zone].”

Conviction remains Nimmo’s most likely path toward staying in the major leagues. His approach must be relentless. He cannot give away an at-bat. He cannot give away a pitch. Absolute confidence in his knowledge of the strike zone is not only his signature but his best chance to make good on the first-round draft choice the Mets utilized to take him in 2011.

“He’s the poster boy,” said general manager Sandy Alderson, who made one of his first acts with the Mets the importing of the ultra-disciplined hitting philosophy he came to value during his days with the Oakland A’s.

Within an organization that has been fanatical about instilling strike zone command and the mental toughness required to execute the approach, Nimmo has been among the most rabid adherents. That devotion must continue even as questions remain about whether it will be enough.

Nimmo is earnest and polite. He does not need reminding of his place within the clubhouse. There is little hint of ego or brashness — until he talks about his command of the strike zone.

Then he brims with confidence, which often comes spilling out on the field. Nimmo does not hesitate to begin his jog to first base when he’s convinced he’s just seen ball four, as he did twice on Wednesday. Nor does he hesitate to shoot a glance or offer a few words when an umpire believes otherwise, as he did twice on Wednesday.

“I do have a lot of confidence and again, it’s just been the process of doing it over and over again,” he said. “And then, now at the major-league level getting everyday playing time and at-bats, I’ve felt more and more comfortable.”

There are flaws in his game. Nimmo is not a natural in centerfield — which hurts his versatility — and many rival talent evaluators do not project that he’ll hit for the power required to stick as an everyday corner outfielder.

Baseball is a game that obsesses about placing players in the proper, neatly defined bin, and Nimmo has never been easy to categorize. He was a first-rounder in 2011 despite playing only American Legion baseball because his home state of Wyoming doesn’t feature high school ball. If his power doesn’t develop, it’s clear that Nimmo will never fit any of those bins, thus lowering his perceived ceiling.

Except the 24-year-old has excelled in his first extended run of playing time. Seizing on an opportunity opened by injuries to others, he has been a fixture in the lineup since Aug. 25 and has a .271/.402/.447 slash line.

“His on-base is tremendous,” manager Terry Collins said. “He’s exactly what everybody has told me, and that is he’s a disciplined guy at the plate. No matter what the count is, he really hunts a pitch he can handle and he’s really done a nice job.”

Nimmo has hit only four homers. But because of his 16.8 percent walk rate since he began playing nearly every day, his on-base skills have made him perhaps the most valuable offensive player on the team. Of the Mets’ regulars, in the final month of the year, only Nimmo has an OPS better than .800.

Playing time has only reinforced his absolute confidence in his knowledge of the strike zone. It has further honed a skill that has become hard-wired into reaction.

“Once you get up to the plate, you have 0.4 seconds to react,” Nimmo said. “So there’s not a whole lot of time for thinking.”

He has swung at only 16.5 percent of pitches out of the zone, fifth best in baseball among those with at least 100 plate appearances. And in September, he has chased a lower percentage of pitches out of the strike zone than Reds star Joey Votto.

Votto, however, hits for power, a gap that Nimmo hopes to bridge. He must be enough of a threat with the bat to deter pitchers from simply attacking him relentlessly. A few swing adjustments have helped.

“His swing has gotten better and better and better,” Long said. “And that’s playing into this equation, because if he’s not doing damage or having good at-bats or making hard contact, they’re going to pound the zone and he’s not going to be able to do anything with it. So I think they go hand in hand.”

Nimmo described “cutting the fat” in his swing by eliminating excess movements that serve as power leaks by keeping his hips from driving the action. Those changes, Long believes, could lead to more power. He did not rule out a spike similar to the one experienced by the Marlins’ Christian Yelich, who went from single-digit home run totals in his first three seasons to the 20-homer range the last two years.

“Do I think that he can be a Christian Yelich? Yeah, I do. I think that’s in there,” Long said. “He’s starting to learn what he can maximize as far as power-wise. He’s still got work to do and he’s still got some room for improvement. But overall, we’re looking at a really, really good player right now who has a little bit higher ceiling. And the ceiling is the power.”

No one knows if the power will come. But with Nimmo, it’s clear that plate discipline will be at the center of his value. So he goes to great lengths to build upon that strength.

Resources abound in the majors. Employing two hitting coaches has become the industry standard, along with sending video coordinators on every road trip. For Nimmo, it has been a revelation. At Triple-A Las Vegas, he’d be lucky to get an over-the-top view of home plate. Here, it is common.

So when he’s burned on a borderline pitch, it sticks. It’s why he found himself in the video room, reviewing the two pitches he thought were balls.

The first was a 96-mph fastball off the outer edge of the plate in his second at-bat that prompted him to say something to plate umpire David Rackley. The second was a high fastball in his final at-bat that should have been the fourth straight pitch out of the zone.

Both times, Nimmo began his jog to first base, only to do an about-face.

Later, he blamed himself. He said “it happens” and that “not every call is going to go your way.” He insisted that he missed pitches to drive, particularly in his last at-bat.

“I don’t think of myself as too high and mighty to admit when a pitch is there,” Nimmo said. “When a pitch is there and you made a good pitch on me, I’ll wear it and I’ll know I should have battled there. But when I feel it’s off, yeah, I’m pretty confident in that. I’ll toss the bat off. But I make mistakes, too.”

Not many, of course. At least, that’s what the numbers have shown. So he twisted his face into a knot, as if he had swallowed a lemon. He will call it like he sees it. And the way he sees it is that he got tough strikes on a pair of borderline pitches that should have been called ball four.

More often than not, the video will show that he is right.

“Those were two pretty easy calls,” Nimmo said, shaking his head. “Should have walked twice.”