MLB

Mets demote Fernandez, Tejada

PORT ST. LUCIE — Fernando Martinez stood in front of his locker in the Mets major league clubhouse yesterday, talking about how he finally felt like he belonged.

“I’ve been here a long time, but now I feel comfortable and I know what I’m doing,” said Martinez, who has had productive spring training. “I’m finally healthy and things are coming together for me. I think today is going to be a good day.”

Shortly after, he was optioned to the minor league camp, along with another prospect the Mets still have high hopes for, Ruben Tejada.

PROSPECTS COUNTDOWN

Manager Terry Collins didn’t rule out the possibility that one or both could be back — in the case of Martinez, as soon as Opening Day, if Carlos Beltran proves to be unavailable.

But Collins stood by both decisions yesterday, even with the right field situation as uncertain as it is and Tejada being clearly the best defensive second baseman in camp. The Mets have been adamant about not letting him compete for a spot, despite the ongoing ugliness at second.

“I want him to go play shortstop,” Collins said — repeatedly — after the Mets beat the Marlins, 10-0 at Digital Domain Park.

With Jose Reyes about to enter the final year of his contract, there is a distinct possibility the Mets will be in the market for a new shortstop and the gifted — and inexpensive — Tejada could be an alternative, either next season or even after this year’s trade deadline.

“You’ve gotta anticipate the possibility of a problem with Jose,” Collins said. “Hopefully there isn’t, but you’ve gotta anticipate it. I want [Tejada] at shortstop every day.”

And the only place for that to happen, at this time, is Triple-A Buffalo.

“Obviously, we’ll have a backup shortstop on this team,” Collins said. “I think this guy has an outstanding future, and we want him playing every day, getting consistent at-bats.”

The same is true for Martinez, who until yesterday looked to be at least in the conversation for considerable time in right should Beltran be out for an extended period of time.

“A lot goes into the fact he hasn’t been able to play [much] the last couple of years because injuries kept him down,” Collins said of Martinez, who was 8-for-22 with a homer and four RBIs this spring. “I watch closely in March, but I don’t get too caught up in March. He had a very good spring swinging the bat and I said, ‘Great, now go put together a real good year.’ ”

Collins didn’t completely rule out Martinez’s return in the near future.

“That’s another situation where you don’t know what’s gonna happen in the next two months, so he has to go someplace to get consistent at-bats,” Collins said. “Absolutely, he could come back Opening Day. If Carlos couldn’t start the year or something else, you could bring those guys back.”

Beltran remains out with left knee tendinitis but said he feels “better.”

“When he tells me he’s ready to play, he’ll be in there,” said Collins, adding that Beltran’s at-bats would take away from the ones Martinez would have gotten, which also led to yesterday’s decision. “I have a target date in my mind, but that may not coincide with how he feels.”

That could mean good news for Martinez, who wasn’t expecting the bad news he got yesterday.

dan.martin@nypost.com