I should have done this before. But spurred on by many e-mails and seeing that Amalie Benjamin educated her readers over on Boston.com, here is the deal on postseason eligibility:
The 25 players on the roster as of midnight on Aug. 31 are eligible along with any players who were on the 15-day or 60-day disabled list.
As of that date, the Yankees had five players on the disabled list. Doug Mientkiewicz, Carl Pavano, Humberto Sanchez and Jose Veras were on the 60 and Ron Villone was on the 15.
So the Yankees have a 30-player pool they can choose from for the postseason. But they can replace Pavano or Sanchez (who are still on the DL) with any player who was in their organization as of Aug. 31.
That means Ian Kennedy, if they want.
Hope that answers your questions.