MIAMI — The Mets came into the season with a strong rotation and a weak defense.

And it has only gotten worse. For everyone.

How a team can be based on pitching yet not fix its defense is mind-boggling. But that’s the Mets and that’s how this team has been built. Some potential deals didn’t pan out and in the end the Mets were caught holding these sub-par defensive cards.

It has been a combination of factors that have created their 41-51 record, and until the defense is fixed, especially up the middle, the Mets will be in the same boat. They cannot possibly go into the same situation in the future and as an organization. They have to correct these problems first.

Shortstop Amed Rosario’s range is poor, the Mets are now playing without a true center fielder, Robinson Cano has slipped at second base and catcher Wilson Ramos’ defensive skills have greatly declined.

So much for being strong up the middle.

The Mets are going to have to prove in the future they value defense more than they have shown in the past. Everybody can’t just be put anywhere.

They would probably be better off sticking Jeff McNeil in left field now and for the future, and put Michael Conforto back where he belongs in right field instead of center field.

They are playing with fire playing those players out of position.

“I can’t believe how bad the Mets are defensively,” a scout at Friday’s 8-4 loss to the Marlins at Marlins Park told The Post. “They are one of the worst teams I’ve seen defensively. Other than Todd Frazier, no one excels defensively.”

Mickey Callaway and his staff have held extra practice sessions to try to improve the defense, but you can’t make Ozzy Osbourne into Ozzie Smith no matter how much practice time is put in on a regular basis.

You are what you are and the Mets have put the accent on offense — defense be damned.

When I asked Callaway on Saturday what he can do about the team’s defense, he said this: “We are going to have to position guys the right way. That is going to be key, we’ve talked to some guys about that, to continue to position ourselves the right way.

“We are third or fourth in the league when we put a shift on,” Callaway said before Noah Syndergaard took the mound against the Marlins’ Zac Gallen, “so we understand that positioning is going to be key.”

The Mets have tried their best to get Rosario in the right position, but he seems to have great difficulty going to his left and many balls that pitchers think are going to be caught somehow make it into center field.

That is a sticking point with pitchers and rightfully so. Pitchers these days often feel they did their job when they get a ground ball, yet so many of those ground balls get through the middle against the Mets. Then in center field, Conforto simply does not have the range.

Conforto is a team player and has moved to center, but should just stay in right. Juan Lagares has struggled mightily and has lost his job in center because of his offensive woes and the Mets are trying something different.

They need to come up with a center fielder through trade or perhaps giving Rosario a shot to play center and see if his reaction time is any better in center than it is at shortstop.

Improving the defense would improve the pitching. Tomas Nido has done a good job behind the plate and has become the pitchers’ favorite catcher. Nido learned a lot last year behind Devin Mesoraco on how to prepare for a game and how to work and help the pitchers think through certain situations. He has been a pleasant surprise.

The bottom line is the Mets have not been able to develop enough solid defensive players and that hole in the system was not plugged this year through free agency or trades.

It is an issue that must be fixed going into next season or the Mets will run into the same problems over and over again, reliving this nightmare.