MIAMI _ At one time this spring, the Mets had only two players _ David Wright and Jose Reyes _ healthy enough to be on the field.

The day before they open the season against the Florida Marlins, the team that officially knocked them from last year’s pennant race, the Mets are still a group with health issues that figure to help determine their final roster.

“I believe our team will come from the players we already have here,” general manager Omar Minaya said.

So, barring an unforeseen trade, the team that will work out this afternoon is the same one that will take the field behind Johan Santana tomorrow.

“We need to stay healthy, that’s the big thing every year,” Wright said. “It seems like we’re coming together now.”

Even so, the Mets’ last four roster decisions will be injury based.

Based on Friday’s exhibition game against Baltimore, the fifth starter will be Orlando Hernandez over Mike Pelfrey because his right foot will be able to take the pressure of his high-kick wind-up.

All along, Pelfrey said, “it’s his job if he’s healthy.”

Of course, the most significant Mets’ pitching question, as it has been in each of the last three years, is the durability of Pedro Martinez.

Martinez took his time getting ready in spring training and did not miss any time because of injury.

However, shoulder surgery always shadows a pitcher. It’s why he made only five starts last season.

The projected number of starts for a frontline starter to make is 33 to 34. Bullpen coach Guy Conti has Martinez penciled in for 27, figuring something will always come up for a 36-year-old pitcher.

“I’m healthy now,” Martinez said. “When I’m healthy, I will be able to do things.”
Martinez’s health is why Pelfrey got a shot last spring, and the latter pitched well enough to earn his spot on the roster.

Not this year with an eight-plus ERA.

Sending Pelfrey to the bullpen instead of Triple-A New Orleans is not an option. He needs the regular work to resolve his mechanical and location issues, and won’t get them as a long-man.

The final spot in the bullpen won’t go to Duaner Sanchez as he promised several times early in camp, but will come down to Joe Smith, Brian Stokes or Nelson Figueroa.

Because of the inevitable options scenario, it figures to be Stokes.

Sanchez, who underwent surgery twice on his shoulder within a year-and-a-half, has shown he can throw hard, but not in back-to-back games.

“That’s something he needs to show he can do,” manager Willie Randolph said.

Ramon Castro’s strained right calf has not responded to treatment, and the team is leaning toward putting him on the disabled list and going with Raul Casanova as Brian Schneider’s back-up.

Finally, the Mets must choose a bench spot between Fernando Tatis and Brady Clark. Both are right-handed hitters.

That factor, and his supposed weakness as a reserve shortstop, were the reasons why Ruben Gotay was waived, but it isn’t unreasonable to suggest they might regret the move on another level.

Luis Castillo is the Mets’ second baseman, but he’s 32 and coming off surgery to both knees.

“I’m better,” said Castillo, who was limited to only 32 at-bats this spring. “But, I’m still not where I want to be.”

Castillo hit .188 in the Florida exhibition games. The Mets could end up missing Gotay if Castillo’s knees act up or his average stays dormant.

There are a lot Mets who say they aren’t where they want to be.

Right now, the most important spring training statistic for hitters are at-bats, and to best understand where the team is, consider recently optioned utility infielder Anderson Hernandez has 53 at-bats.

That’s more than six of the Mets’ projected Opening Day starters: Ryan Church (52), Carlos Delgado (42), Carlos Beltran (41), Castillo, Brian Schneider (12) and Moises Alou (10).

Beltran underwent surgery on both knees and is not 100 percent, which could factor as an advantage for keeping Clark.

Delgado missed time with a right hip impingement and has been slow in finding his timing. He’s hitting .214, and after an injury-dominated off-year last season, at 35, there’s reason for concern.

Like it or not, Randolph has his team.

However, his overriding concern is their ability to stay in one piece.