NEW YORK -- Coming off one of the best individual seasons of his career, Yankees closer Mariano Rivera has opted to undergo arthroscopic surgery on his sore right shoulder.

Tests taken earlier this week in New York revealed inflammation and calcification in the 38-year-old's right shoulder. The club has not officially released a date for the procedure, but Rivera is expected to be ready for Spring Training.

Yankees manager Joe Girardi revealed Rivera's decision as several members of the roster cleaned out their lockers at Yankee Stadium, heading into the offseason and facing the Yankees' first dark October in 13 seasons.

"I think this is what Mo feels most comfortable with," Girardi said. "Fortunately for us, it's not something like when you hear shoulder, you hear rotator cuff or labrum. It's not that. It's a little calcium deposit that they just shave down."

Rivera addressed reporters on Friday at Boston's Fenway Park and said he had been told that surgery was one of two options that could correct the ailment. Rivera could also have alleviated the soreness with a series of periodic cortisone injections, but said, "I hate needles."

"I just think he's more comfortable having it done and then it's not an issue for next year," Girardi said.

Despite pitching with the ailment all season, Rivera assembled one of his best statistical seasons, converting 39 of 40 save opportunities to go 6-5 with a team-leading 1.40 ERA, pitching in 64 games overall.

"You learn how to deal with it," Rivera said. "Obviously, there are days that you won't pitch because it hurts, because it's cranky, but I'm here to pitch. I don't come here to sit down and just see what happens."

His final appearance came in the first game of New York's day-night doubleheader at Fenway Park on Sunday, as Rivera recorded the final four outs to preserve Mike Mussina's 20th victory.

Earlier this season, Rivera -- who is signed through 2010 -- surpassed Lee Smith for second place on baseball's all-time saves list with 482 in the regular season, plus 34 more in his playoff career.

"I want to do what I'm doing for the next two years," Rivera said. "If the injections or the surgery will be the best, I have to choose the right decision."

In other injury-related updates, Hideki Matsui had arthroscopic surgery to repair cartilage damage in his left knee last Monday in New York. He believes that he will be prepared to help the Yankees next season after having a similar injury corrected on his right knee last season.

"It was basically the same procedure as last year," Matsui said through an interpreter. "As long as I rehab and make sure I prepare for Spring Training next year, I should be fine. It should be much better condition compared to this past season."

Matsui, 34, completed the season batting .294 with nine home runs and 45 RBIs, returning to the club in August after the injury limited him to duty as a designated hitter. Matsui is hopeful that he will be able to return to defensive duty in the outfield, but that may depend on the Yankees' winter.

"We expect him to be healthy all year, and we think we'll have a pretty good player again," Girardi said.

Backup catcher Jose Molina said that he plans to alter his training program to reflect potential uncertainty with Jorge Posada. The switch-hitting Posada missed most of this season with a strained right shoulder that required season-ending surgery on July 30.

Posada has vowed to be ready to catch on Opening Day at the new Yankee Stadium in April, projecting that he will catch about 120 games next season. Molina was pressed into duty to catch 100 games for New York in 2008 after catching only 69 the previous year, 29 of which were for the Yankees.

"My preparation in the offseason will change this year," Molina said. "It won't be the same way that it was last year. It was great in the offseason, but I think I'd better add some other stuff too."

Right-hander Chien-Ming Wang, sidelined since June, will continue his throwing program in Tampa, Fla., over the winter. Girardi said that there were no other pressing medical issues with his club, which completed play on Sunday with a final record of 89-73.

"I think that guys are fairly healthy," Girardi said. "Tired, maybe, going into the offseason. Everyone looked pretty good to me."