I'm going to steal nyyrocks29's first paragraph, but disagree with his definite postseason roster players.
Barring an absolute miracle from the Red Sox, the Yankees, whether they win the division or wild card, are heading to their 14th postseason in 15 years. They're obviously going to set their lineups and roster for the postseason in the near future. Some of those calls for spots will be easy, others will be more difficult. I'll hit the definite ones first.
Catchers: Jorge Posada, Francisco Cervelli
First Base: Mark Teixeira, Lance Berkman
Second Base: Robinson Cano
Third Base: Alex Rodriguez
Shortstop: Derek Jeter
Outfielders: Brett Gardner, Curtis Granderson, Nick Swisher, Marcus Thames
Starting Pitchers: CC Sabathia, Andy Pettitte, Phil Hughes, A.J. Burnett
Relief Pitchers: Javier Vazquez, Boone Logan, Joba Chamberlain, David Robertson, Kerry Wood, Mariano Rivera
That makes 21. I disagree completely that Chad Gaudin will be a definite. As a matter of fact I don't think he will make the roster at all. Sure, Joe Girardi likes him, but Girardi likes Mitre more. I'm not willing to give Mitre a definite spot either, as Nova may get the spot over him even.
For now I put Pettitte as a definite, as he should be fully healthy by the playoffs unless he gets re-injured.
Kearns is also not a definite. Kearns would be a nice guy to have off the bench, but Thames is on the roster for a reason, and that is to face lefties. If Granderson needs to be benched, which he shouldn't, Thames may have to play the field, as bad as that sounds. Personally, I'd rather have Greg Golson on the roster.
While it would be nice to say Javier Vazquez won't be on the playoff roster, barring an injury or him beating up Joe Girardi in an alley, he will be on the roster. That shouldn't be the case, but knowing the Yankees, it will be.
Anyway, we're at 21. To fill the spots I'd like to narrow it down to Jonathan Albaladejo, Sergio Mitre, Ivan Nova, Royce Ring, Chad Moeller, Eduardo Nunez, Ramiro Pena, Greg Golson, and Austin Kearns.
The Yankees need a long reliever on the roster. My choice? Sergio Mitre. He has experience, his nickname is even "The Experience", and he has pitched well the majority of the season. Nova pitched great this year in AAA and has pitched well in the majors, but he isn't a sure thing in the majors just yet. Chad Gaudin shouldn't even be in consideration.
That's 22. Now the Yankees need a utility infielder. The choices are Ramiro Pena and Eduardo Nunez. My choice? Eduardo Nunez. It's a very tough choice to make, considering Pena has the better glove, but if the Yankees ever, ever need a late inning replacement, or an injury replacement, or any kind of replacement, the Yankees shouldn't give the other teams outs with Ramiro Pena in the lineup.
That's 23. Two spots left, a fifth outfielder needed. The choices are Austin Kearns and Greg Golson. My choice? Definitely Greg Golson. Golson has a cannon arm, as we've seen before. Golson can run and run and run and run his way onto the playoff roster. He can be this years Freddy Guzman, a late inning pinch-runner/defensive replacement. As mentioned before, Kearns is a nice bat to have off the bench, but not necessary.
That's 24. One spot left. The choices are Albaladejo, a one-inning reliever that has pitched well, Nova, a long reliever that has pitched well, Ring, a lefty reliever that really would only get near the roster if he pitches well against lefties for the rest of the regular season, Moeller, a 3rd catcher, Pena, a 2nd utility player and pinch runner, and Kearns, a bat off the bench. My choice? Albaladejo. He pitched really well this season and got called up a bit too late. He can pitch an inning or two in a close game if needed, and that may be needed. Nova or Pena would be fine choices as well.
That's 25. As for the rotation, I'd have CC go game one, Pettitte pitch game two, Hughes in game three, and Burnett in game four.
The lineup should have Gardner first and Jeter second, outside of that, as long as Granderson is playing every day, I'm fine with almost anything.