On an underachieving team with hefty contracts that largely have not worked during the first three months of the season, Brandon Nimmo stands out.

Is the Mets outfielder only getting better after he signed an eight-year, $162 million pact this offseason?

Nimmo’s slow but steady rise, from a raw, developing prospect from Wyoming to a borderline star, has been incremental.

First the former first-round pick proved he could play in the big leagues.

Then he conquered left-handed pitching to display he is an everyday player.

Next came becoming a playable option in center field, and what followed was mastering the spot that has become his home.

In Year 8 of his career and Year 1 of his new deal, Nimmo has flashed power that was untapped previously.

The 30-year-old has smoked 12 home runs in his first 82 games, on pace for 23.

Nimmo has never smacked more than 17 in a season, but slugging has become his area of improvement this year.

“It’s been a focus for sure. I knew there was more inside of me,” said Nimmo, who is hitting the ball (an average exit velocity of 91.7 mph) harder than ever. “I was hitting balls [in previous years] at an exit velo that, if I was getting them in the air consistently, would produce more home runs.”

This season, the leadoff hitter is hitting fewer balls on the ground.

He called his swing adjustments a balance and does not want to lose the skills that make him so valuable at the top of the order.

He is striking out slightly more, but he will accept that trade-off when the power is there.

Nimmo stayed healthy and productive last year, using solid defense and an .800 OPS to launch him into his large contract.

This year, his OPS is up to .830.

“It’s a little bit of a mindset change,” said Nimmo, who credited hitting coach Jeremy Barnes with the tweaks to elevate pitches. “It’s a little bit of a swing-plane change.”

It has added up to a little bit of a different Nimmo.

In his past 22 games, Nimmo has slugged eight home runs and posted a .941 OPS, a rare consistent (and powerful) piece of a lineup that has not been good enough.

“He’s a strong guy. We’d all like to come back in our next lives with Brandon’s look,” manager Buck Showalter said this weekend. “I wouldn’t preclude him from doing anything. He’s growing every day.”

Seemingly every year, Nimmo becomes a stronger All-Star candidate, but no season thus far has made him an All-Star.

Nimmo entered Monday’s off day, when the Mets traveled to Arizona, as the sixth-most valuable outfielder in the National League, according to FanGraphs’ WAR rankings.

The top four (Ronald Acuna Jr., Mookie Betts, Corbin Carroll and Juan Soto) were named All-Stars on Sunday.

Also selected were Lourdes Gurriel Jr. (17th) and Nick Castellanos (12th), who were the lone representatives of the Diamondbacks and Phillies, respectively.

The only more valuable outfielder than Nimmo, by FanGraphs’ measure, who did not win the trip to Seattle was Fernando Tatis Jr., who might have been punished for his PED suspension.

Previous to the announcement, Nimmo said the All-Star Game is “definitely something I’d like to cross off.”

He was an All-Star at every level of the minors apart from Triple-A — “and that was because I got called up in June [of 2016],” Nimmo said — but has fallen short each major league season.

“I feel like I’ve played well enough to get there,” said Nimmo, who still could be added to the NL roster. “But it’s not the end goal for this team. I definitely want to achieve personal things along the way.

“An All-Star nod would be amazing, would be something great to have. … I’ve been really happy with [my play] and helped us try to win ballgames, and that’s my main concern, is at the end of the year being in the playoffs and giving us a chance to win the World Series.”

It’s a long shot for the 38-46 Mets, but where would they be without their most consistent weapon?

“It doesn’t really surprise us anything that Nimm does,” Showalter said.