Here's how it breaks down:
The primary reason to take the "A" series for the ALDS was that the extra off day permits the team to use just three starters. The secondary benefit was that the schedule gave the Yankees the option to carry just 10 pitchers, allowing an extra position player on the bench. While it's hard to argue against the presence of any of the eleven pitchers on the roster, the Yankees have punted on the opportunity to bolster the bench.
Pitchers (11): Sabathia, Burnett, Pettitte, Rivera, Hughes, Aceves, Robertson, Coke, Marte, Chamberlain, Gaudin
Catchers (3): Posada, Molina, Cervelli
Infielders (5): Teixeira, Cano, Jeter, Rodriguez, Hairston
Outfielders (5): Damon, Cabrera, Swisher, Gardner, Hinske
DH (1): Matsui
The presence of Marte and Coke both is necessitated by the Twins' dangerous lefty combo of Joe Mauer and Jason Kubel. Having both Joba Chamberlain and Chad Gaudin is somewhat redundant, but in my opinion both are equally worthy of a roster spot. However, given the way the schedule shakes out, neither pitcher should be used too heavily unless there is an extremely long game. The off days should allow Mo, Hughes, Alf, DRob and the lefties to pitch the bulk of the relief innings.
The Yankee bench is further shortened by the decision to have Jose Molina catch A.J. Burnett in Game 2. This is the only conceivable reason to have Francisco Cervelli on the roster. I like Cervelli as much as the next Yankee fan, and I hope to see him as the back up catcher next year. But barring something disastrous, he shouldn't see the field in the ALDS.
I have mixed feelings about Molina catching Burnett. While it appears that Burnett works better with Molina, I'm not convinced that's the case nor am I convinced of the reliability of the small sample size of data that supports the decision. Either way, the lack of Posada's bat in the line up, and replacing it with Molina's, could negate any perceived or realized advantage on the other side of the ball.
Furthermore, I hope that Cervelli's presence isn't an indication the Posada will DH when Molina catches. Replacing Matsui with Posada is a wash at best, particularly with Matsui's success against southpaws. Confining Posada to DH duty means that Cervelli, who is an incremental offensive upgrade over Molina, would enter the line up when Molina is inevitably pinch hit for in the late innings. Otherwise, the Yankees will lose the DH if Posada moves from DH to behind the plate.
Cervelli's presence also means that Ramiro Pena and Freddy Guzman are off the roster. I certainly haven't been an advocate of having Guzman present for the express purpose of pinch running. However, his absence likely means that Melky Cabrera will be the centerfielder, with Gardner coming off the bench as a pinch runner. As Jay and I have covered several times over the course of the year, we feel that Gardner is the better choice for centerfield.
Pena on the other hand, offers about the same offensive value as Cervelli, with the added benefit of being more versatile defensively and a better pinch running option. While the Yankees shouldn't need one, let alone two utility infielders, having both Hairston and Pena on the roster would allow them to spell both Jeter and A-Rod should a game get out of hand.
In the end, this is all probably much ado about nothing. Given the talent level at the top of the Yankees roster, if the series comes down to the 24th or 25th man on the roster things are likely pretty well screwed anyway. However, as we discussed at over the course of this season, each roster spot is a resource that needs to be allocated in the best way possible. I'm not convinced that this particular group of 25 is the best use of the Yankees resources for the ALDS.