Jorge Posada’s reported decision to retire before the start of spring training reduces what had been the Core Four and then the We Three down to the True Two.

But that is not as bleak as it may appear in the first blush of the news over the weekend.

While it might seem as if Posada’s departure signifies a further dismantling of those great Yankee teams that won four World Series in five years and then added another in 2009, the effect of this loss is purely nostalgic.

Although the retirement of Andy Pettitte last spring left the Yankees seriously short of starting pitching, the Yankees really didn’t have a spot for Posada on their roster for 2012.

And while it is true that Posada was a key part of those championship teams, it is difficult to make the argument that the Yankees could not have won without him. (In fact, they did win that first championship in 1996 with a different catcher. Guy named Girardi).

However, it is impossible not to argue that the two who remain -- Derek Jeter and Mariano Rivera, the True Two -- were the most important parts of all those clubs, and remain strong and valuable members of the Yankees at least through the end of this season and in the case of Jeter, probably through 2014.

As great as Posada was -- and although I haven’t done more than a surface look at the numbers, he is probably getting my vote for Cooperstown -- the Yankees clubhouse always revolved around Jeter, and many of their most important games came down to Rivera.

Unfortunately for Posada, his offensive contributions were often overshadowed and overlooked by teammates such as Bernie Williams, Tino Martinez, Paul O’Neill and even in 1998, Scott Brosius, and the grumbling of some Yankee pitchers in recent years about his game-calling has cast a pall over what for the most part were better-than-average defensive skills.

And the Yankee roster, for the past 15 years a rotating cast of high-profile, high-salary, and sometimes high-maintenance characters, is a very tough place to stand out in.

It was Posada’s unfortunate lot to never really have been the focus of the attention from fans or the media when he was at his best. Sadly, he drew the most scrutiny in 2011, when he was at his worst. Certainly, he deserved better than that.

But the Yankees will survive his absence, the same way they got by without Pettitte with a a rotation cobbled together out of one ace, two retreads, a rookie and a talented but erratic head case.

Russell Martin proved himself a more than adequate replacement for Posada behind the plate last year, and Jesus Montero showed enough promise in September to allay any fears that the Yankees lineup will suffer the loss of Posada, especially the 40-year-old version that could no longer hit lefties.

We will miss Posada’s heart and his passion and, those of us who covered him, his candor in a clubhouse filled with diplomats.

But the Yankees will go one, because there is still Jeter to set the tone in the dugout and Mariano to settle the score at the end of the game.

The Yankees are in transition, no doubt, and within three years, the last remaining player from that era will probably be gone. But as long as Jeter and Mariano are still in that room, the spirit of Steinbrenner’s Yankees and Torre’s Yankees and O’Neill’s Yankees and Bernie’s Yankees and Tino’s Yankees lives on.

When the True Two becomes the No Mo, that’s when Yankees fans will have something not just to cry about, but to worry over.