The Mets left Port St. Lucie with full steam ahead and even got a last-minute boost from Francisco Lindor’s contract extension on the eve of Opening Day.

They have spent seven of the next 12 days not playing baseball.

A mix of COVID-19 issues, scheduled off days and, most recently, weather headaches — including another postponement Monday night at Citi Field — has thrown the start of their season into disarray. The stop-and-start conditions have disrupted the Mets’ chances to get into a rhythm offensively, and they believe the results have shown in the early going.

“The biggest thing is to simulate game speed for us,” manager Luis Rojas said Monday before the series opener with the Phillies was postponed to be part of a doubleheader on Tuesday. “I think you can keep everyone ready, we can have a script of things so we keep everyone active in every area. But to simulate game speed, when everyone else is playing, is our challenge. We’ve seen a little bit of the results when we’ve been interrupted, and we’ve felt pretty good that we did everything we had to do just for the guys to be ready when we started playing again.”

If their schedule had gone according to plan, the Mets would have been playing their 10th game in 12 days Monday night. Instead, they were still left waiting to play their sixth game of the season — less than any other team had played through Monday, including the Nationals, whose COVID-19 issues postponed the scheduled season-opening series between the two teams.

The small sample size and lack of consistent games have allowed a number of poor-looking stat lines to linger — the big one being that the Mets were batting just .146 and slugging .171 with runners in scoring position. Hitting in those pressure situations is among the areas that cannot be fully simulated in an indoor batting cage, as much as the Mets may try.

“Really tough to simulate exactly the timing mechanism and to simulate the emotions you get flowing in games,” Rojas said. “Those emotions flowing, the adrenaline, the fans that we have now being present that have their impressions when there’s a big situation — bases loaded, one out, that we’ve had a couple times when we haven’t really delivered a big hit. That’s the only thing we’re missing, is just playing in games and getting more repetitions of those situations where the guys are now seeing it and they’re freeing up a little more.”

Michael Conforto, who was set to be dropped to sixth in the lineup Monday before the game was postponed, has been among the biggest culprits for the Mets’ early struggles, but he wasn’t exactly alone in that regard. Lindor, Jeff McNeil and James McCann were also stuck below the Mendoza line through five games, lacking any kind of consistent at-bats to snap out of their slow starts.

Confined to indoor work in the absence of games, Mets batters have been turning to pitching machines that can offer both breaking balls and high velocity. But those can only help so much.

“Once we start playing games and we can translate some of the things we’ve been doing to the games and guys get their repetitions, we’re going to get everyone ready, competing at their best,” Rojas said. “We’ve seen some guys that have been late on fastballs. We’ve seen some guys not being able to recognize breaking balls well. And we’ve seen some relievers coming out of the chute and not being effective against the first batter that first inning.

“That’s definitely been the biggest challenge is simulating all of that, but what can you do? We’ll get to play, and we’re gonna play a lot of games. I think we’re going to get to that ready-position feel that we need to be.”