Short Answer: They got old fast.

Posada, Bernie, Mussina, Gordon, Rivera, and Randy Johnson are all past their prime, and, with the possible exception of Johnson and Rivera, it's unrealistic to expect them to perform at the same level that they have in the past.

Also don't forget that as players age, even if they keep their performance level up, they become more prone to injuries.

Giambi, Tino, Quantrill (and the rest of the bullpen) and Kevin Brown are basically useless, and Womack is a nothing anyway and certainly no better than Miguel Cairo.

I wouldn't count them out just yet, but if Sheffield starts to show his age anytime this season, either by a performance drop-off or with an injury, and either Johnson, Pavano, or Mussina misses many starts, don't be surprised if the Yanks finish around .500