First off, we don't really know exactly how long Posada will be out: The Yankees say he'll return to the lineup in three to four weeks, but he says he'll be back sooner. For argument's sake, let's expect the worst, which is that he'll return to the lineup a month from now. We don't think that's such a bad thing.
Not to diminish Posada's value to this team when he's healthy — he leads the club in slugging and OPS — but even though he's signed through 2011, the Yankees ought to start thinking about who will eventually replace him. Not long ago, we would have assumed the answer would have been either Jesus Montero or Austin Romine, as soon as one of them proved himself ready. After all, the two young catchers are the jewels of the Yankees' farm system, and their development, if all goes well — and that's a big if: Montero has struggled at AAA this year, and Romine's still at AA Trenton — should coincide with the tail end of Posada's contract.
But the Yankees have to start seriously considering whether Francisco Cervelli is for real. Cervelli joined the team without much fanfare last year — he jumped from AA to the majors largely because he was already on the 40-man roster when the team needed a catcher, and only saw playing time because both Posada and Jose Molina got hurt — but played well enough to earn the backup job in 2010. But he hadn't hit particularly well in the Minor Leagues — over five seasons, he hit .273 in the Minors, and batted just .233 last year while spending time at three different levels — which is what makes his 2010 numbers all the more curious: He's hitting .373 with a .442 OBP in 81 plate appearances, and he's hit a ridiculous .611 with runners in scoring position. Plus his defensive skills and ability to call a game have never been in question (which is more than we can say for Montero).
We want to be clear, though: We're not arguing that the Yankees are better off with Cervelli over Posada. But Posada's injury gives them a golden opportunity to evaluate Cervelli now that he'll be forced to become an everyday player. (Chad Moeller will serve as his backup.) At some point, the Yankees will have to decide which of these catchers is their future and which are trade bait. Here's Cervelli's chance to prove he's the former.