Wang took the first step on Wednesday, undergoing season-ending surgery on his right shoulder capsule in Birmingham, Ala., under the care of Dr. James Andrews.
The Yankees were not immediately provided with an estimated return time, but word filtered back to Tropicana Field that Wang had a tear in his capsule -- a fibrous membrane that surrounds the shoulder joint and contains ligaments that stabilize the joint.
The surgery is more similar to the procedure Posada underwent after the 2001 World Series than the one that he had last July, which kept him out of Spring Training games until mid-March.
While Posada obviously could not know the medical specifics about Wang's shoulder, he said that rehabilitation exercises actually helped his shoulder for the next season and predicted the same for the right-hander.
"I think he's going to be stronger," Posada said. "I really think so. When everything is intact and where it needs to be, he does all that rehab and strength work, he's going to be a lot stronger."
The 29-year-old Wang's career took an irreversible turn last June 15 in Houston, when he suffered a midfoot sprain of his right Lisfranc ligament and a partial tear of the peroneal longus tendon in his right foot, eventually creating a chain reaction of events.
After coming through Spring Training this season apparently healthy but ineffective in the regular season, Wang again spent time on the disabled list from April 24-May 22 with weakness in the abductor muscles of both hips before leaving a July 4 start with pain in his right shoulder.
"He's been through a lot, but I think he's still young and he's got a lot to go," Posada said. "You've got to stay positive. Now he knows and understands what's going on with his shoulder, and he can really look forward to being healthy again."
Wang's absence has left the Yankees scampering for solutions. Right-hander Sergio Mitre will make his third start since being called up from Triple-A Scranton/Wilkes-Barre on Thursday in Chicago, but general manager Brian Cashman has expressed a need to acquire organizational depth.
On a day when the Yankees officially released veteran Brett Tomko, Cashman made a Minor League move to acquire right-hander Jason Hirsh from the Rockies and assigned him to Triple-A.
Other options in case of emergency include transitioning relievers Alfredo Aceves or Phil Hughes from the bullpen, processes that would not be considered if Wang were healthy and active.
"We're certainly going to miss him later in the season," Posada said. "The games start meaning more and more. As the rotation keeps turning around, you do miss him."
It remains to be seen if Wang's next Major League pitch will even come with the Yankees, the only team he has known after signing as a non-drafted free agent in May 2000.
Wang is under contract for $5 million this season, and as an arbitration-eligible player, New York can only offer a maximum pay cut of 20 percent -- $4 million -- for 2010.
Should Wang's recovery take him deep into next season, the Bombers may decide that extending that sum would be financially unwise.
"I hope not. I hope it's not the case," Posada said. "I think of Wang as a Yankee, and he wants to be here. He's done amazing for us. I don't think of him in another uniform."
Manager Joe Girardi said that it was too soon to know what the future might hold.
"You always expect that all of your players are going to come back," Girardi said. "You always think of Chien-Ming Wang as a Yankee, because that's all we've known him as. That's more for the offseason than now."