PORT ST. LUCIE — Buck Showalter increased the decibels in Mets camp Thursday.

In an attempt to acclimate his team to game conditions, the Mets manager employed piped-in crowd noise during a pop-up drill on Clover Park’s main field.

It’s a tactic Showalter used in previous spring camps in Sarasota, Fla., while managing the Orioles.

“We want to play in front of a big crowd, and in spring training the drills are easy when [it’s so quiet] you can hear on Field 1 what they are screaming in the stadium,” Francisco Lindor said. “So I think Buck had a good idea.”

Showalter led the defensive drills, barking out orders on positioning on cutoff throws. In a condensed spring training caused by the lockout, Showalter wants to ensure the details aren’t getting lost.

“You don’t want to ever do something that is eyewash,” Showalter said. “It’s got to be productive for being a better club.”

Among the other initiatives on which Showalter collaborated was an increase on the number of night games played at home this spring. The Mets have four games scheduled to start at 6 p.m. at Clover Park. It’s an increase from the one or two night games (over a full exhibition season) the Mets have traditionally played.

“I like that,” Lindor said. “I don’t have to get here at 6:30 [a.m.]. I understand the start-early, finish-early, have dinner at home, but we’re night guys. We’re night owls.”

Jacob deGrom declined to say whether he’s among the Mets’ vaccinated players. In recent days, Max Scherzer, Jeff McNeil and Robinson Cano have indicated to The Post they are vaccinated against COVID-19. Brandon Nimmo, Pete Alonso, Dominic Smith and J.D. Davis have also declined to say whether or not they are vaccinated.

A vaccine mandate remains in place in New York for players, preventing those unvaccinated from participating at Citi Field or Yankee Stadium. The Mets’ first home game is scheduled for April 15.

Starling Marte is still dealing with oblique discomfort, but has been participating in workouts that don’t involve swinging the bat.

Left-hander Josh Walker will get the start for the Grapefruit League opener Saturday night against the Nationals in West Palm Beach. David Peterson, Scherzer and deGrom will start the ensuing three games.

The Mets will play an intrasquad scrimmage of five or six innings on Friday at 1 p.m. that is free and open to the public.