Mets, J.D. Martinez agree to one-year, $12 million contract

PORT ST. LUCIE — Mets officials refused to completely dismiss the idea of adding another bat to the lineup as spring training progressed, and Thursday night they pounced.

J.D. Martinez, the top remaining offensive player on the market, reached agreement with the Mets on a one-year contract worth $12 million, pending a physical, according to an industry source. The Post’s Jon Heyman first reported the deal.

The source confirmed that under terms of the contract Martinez will receive $4.5 million this season with the rest deferred, allowing the Mets to reduce their luxury-tax hit from the signing.

Martinez will receive $1.5 million in deferrals each year from 2034-38.

Martinez, 36, recently declined an offer from the Giants worth $15 million because of concerns about the pitcher-friendly home ballpark in San Francisco.

He is among the stable of Scott Boras clients — including Cody Bellinger, Blake Snell and Matt Chapman — who was still available after spring training started. Martinez will lengthen the Mets’ lineup and provide protection for Pete Alonso.

The Post reported before the start of camp that the Mets and Martinez were still talking, and the team might be open to a deal if the price was right.

Martinez, a full-time DH, owned a .271/.321/.572 slash line with 33 homers and 103 RBIs in 113 games last season for the Dodgers.

He has a history with president of baseball operations David Stearns from the Astros, where Martinez broke into the major leagues when Stearns was a young assistant GM for the team.

Martinez’s arrival to the Mets will impact primarily Mark Vientos, who was in position to receive perhaps the bulk of the team’s at-bats as the DH.

It’s conceivable the Mets could carry Martinez and Vientos on the roster, with the latter receiving occasional turns at third base and off the bench.

But the Mets might also decide Vientos would be better served returning to Triple-A Syracuse to receive regular at-bats.

The Mets last week pursued a different J.D. — J.D. Davis — as somebody who could provide insurance at third base and in the DH spot.

But Davis, who was released by the Giants, chose a deal with the Athletics because he was guaranteed playing time.

Stearns left the door ajar last week for the Mets to add a bat, even amid the organization’s commitment to giving young players such as Brett Baty and Vientos an opportunity.

“I still think it’s important for us to give young players who have consistently succeeded at the minor league level chances to contribute in the major leagues,” Stearns said last Friday. “I think that’s important. Those two guys [Baty and Vientos] fall into that category.

“I have also been consistent that it needs to happen over the course of the year. It may not need to happen exactly on Opening Day.”

Also, Stearns perhaps provided a hint last week that Martinez was an option when he was asked about the DH spot.

“That is one of the questions we are going to continue to answer here over the next couple of weeks,” Stearns said last Friday. “It could be our rotation through some of our regulars. It could be more geared toward one of the bat-first players who are here in camp, … but I don’t think we have an answer to that right now.”

As a team above the top-tier luxury tax threshold of $290 million, the Mets are paying a 110 percent penalty on new payroll additions.

Once the deferrals are factored, the Mets’ luxury tax hit for Martinez is about $9 million, according to sources.