So the title for this post is two-fold: first, because I'm a terrible blogger and this post is wayyy overdue. Sorry. Second, because Pettitte's return is a little too late in his career. The man will be forty years old in June, and given his history, you have to believe there will be some suspicions if he's too successful this season, especially with his recent history of muscle injuries.
Because he was ostensibly "retired" last season, Bill James has no 2012 projection for Pettitte. He does, however, have a projection for 2011 based on his last year pitching in the majors, 2010. James projected 23 starts, 140 IP, 9 wins, 7 losses, and an ERA of 3.86. These are very respectable numbers - but if we take into account what has changed since late 2010 when James made these projections, I think we can assume they might be slightly lower.
Pettitte has not played in a major league ballgame since 2010, and for all he says that he's been throwing at home, I think we can assume he will backslide some from the 11-3, 3.28 ERA performance from that year (which is interesting in itself, as it followed four years of ERAs over 4).
He is also looking at extended Spring Training, as he showed up out of retirement well after his teammates had reported - if all goes according to plan, he's looking at a mid-May return, cutting that innings estimate down. Pettitte also lacks the luxury of an assured rotation spot that he would have had in 2011, and has to fight his way into a rotation that is already overcrowded (as a Sox fan, I hope they make room for him by taking out someone young and strong).
There's really no way to guess how Pettitte's return will be - whether it's triumphant or embarassing will be up to his readiness, the state of the team when he returns to it, and Manaer Joe Girardi's decisions concerning his playing time. But it should be interesting - obviously, the players from the late-90s glory days can't stay away - perhaps we should be on the lookout for Jorge Posada to renege on his retirement next season.