Mariano Rivera spoke to the media on Friday, revealing that he has been pitching with shoulder pain all season, but had decided not to tell anyone until Wednesday, when he asked that it be examined. According to Bryan Hoch:

Yankees closer Mariano Rivera said on Friday that he has been pitching with a right shoulder issue and will consider giving a green light to a minor arthroscopic procedure after the regular season concludes.

Rivera said that results of tests taken in New York on Thursday revealed inflammation and calcification in his pitching shoulder. Surgery is one of two options that could correct the ailment, though Rivera could also alleviate the soreness with a series of continuing cortisone injections.

Reportedly, Mo is leaning toward the surgery, which would only require a few weeks of rehab, so he would be fully ready to go back to work in 2009.

Mo will be ready to pitch on Sunday, in support of Mike Mussina's effort to win 20 games in a season for the first time.