If the season were to start today, the Yankees would be handing CC Sabathia the ball, and then Burnett, Pettitte, Chamberlain, and Hughes on the following days. Not a bad rotation in the least, and one that would likely prove to be an improvement over last year’s, which consisted of the corpse of Chien-Ming Wang, juicing failure Sergio Mitre, and the man who attempted to pass of a fox tail as goatee, Chad Gaudin. Good times!
Anyway, there is a chance Burnett will miss some time over the course of the season, Pettitte will turn 38 in the summer, and Hughes will have the number of innings and starts restricted. As it stands, Alfredo Aceves and Gaudin would be the first two to step in if a starter goes down. Both are serviceable arms, especially Ace out of the pen, but neither really are suited to start more than one isolated game at a time.
With the setup role vacated by Hughes, it seems that either David Robertson, Damaso Marte, or a combination will command the eighth inning. D-Rob was particularly useful down the stretch, and Marte was as much of a revelation as a proven reliever can be in the World Series. However, most should handle the seventh inning to start. If Robertson continues to build on 2009, then perhaps he would be promoted, and the same goes for Marte if he regains his pre-2009 form, but for now, the setup role remains effectively vacant. So, there are two roles that the Yanks cannot adequately fill in-house.