Not only will Bailey be unable to pitch again this season, but he could miss as much as half of 2014.
"There were no guarantees [even] if he were able to get back to the mound to a normal level through the conservative path," said Red Sox manager John Farrell. "I think as Andrew weighed all the information that he got from the multiple doctors seen, it was pretty clear cut, the decision. The decision was pretty much made for him."
Acquired to be Boston's closer in December 2011, Bailey has seen his time with the Red Sox marked mainly by injury.
He had an excellent stretch of pitching earlier this season but was first troubled by a right biceps injury, then the shoulder.
There would seem a strong chance the Red Sox will decline to tender Bailey a contract this winter, making him a free agent. However, they could bring him back on a low-risk, less lucrative deal after that.