have surgery on his throwing shoulder, after initially hoping to return to the team as a DH. The original plan had Posada putting off surgery, rehabbing and coming back in a lesser role. That plan would probably mean Posada would have had the surgery in the offseason, making it unlikely that he would be ready for the start of the 2009 campaign.
Even with the surgery it's not a guarantee that he will be ready for the opener next year, but it's a smarter move. The timetable for recovery is six months, which would have him ready right around February when pitchers and catchers report to camp, if all goes well.
The Yankees don't need another DH/1B (See: Jason Giambi, Richie Sexson, Wilson Betemit) so there really isn't room for Posada this year, especially with the recent acquisition of Xavier Nady. Smarter heads have prevailed, also protecting the Yankees four-year investment in the slugger.