We don’t yet know how prepared for the postseason Jesus Montero will be. For now, the Yankees are going to try him at DH, and his initial debut has been enormously positive. However, the Yankees seem to recognize that Montero is their best bet at DH right now (and has been for some time, if not all season) over Jorge Posada, especially against left-handed pitching.
If Montero settles in as the full-time, everyday DH (which he should), I don’t think that there is any justification for giving Jorge Posada a spot on the postseason roster. If the Yankees carry 9 regular position players, 4 starting pitchers, and their six core relief pitchers (Rivera, Soriano, Robertson, Logan, Wade, Ayala), Francisco Cervelli, Andruw Jones, and Eduardo Nunez, the roster will be left with just three open roster spots. One will undoubtedly go to Eric Chavez, leaving two roster spots open. I’d expect one to be devoted to one of the Yankees’ six starting pitchers (likely Phil Hughes) out of the bullpen.
That leaves the Yankees one spot open for a 25th man. Could Posada be that player? I honestly don’t think that there are any good arguments for him at that point. Andruw Jones and Eric Chavez are more capable pinch hitters from their chosen sides of the plate. The Yankees still lack a 5th outfielder and second pinch runner, suggesting someone like Chris Dickerson or Greg Golson. I can’t see any pitching additions that would be particularly wise choices, although the Yankees may be tempted to add another left-handed pitcher in Aaron Laffey or Raul Valdes. Dellin Betances may be a sleeper, and Hector Noesi also has a strong case.
The simple fact of the matter is that Jorge Posada is not a very useful baseball player anymore. He’s a below-average switch hitter who can’t run or field a position. The Yankees do not need his services as a pinch hitter in the playoffs, and will likely have a better option everyday at DH. I could hurt to watch Derek Jeter and Mariano Rivera march off on yet another playoff hunt while leaving Posada behind, but I think we could see it. At the very least, the Yankees would have to be pretty sentimental to keep Posada on the team over more useful options.