SAN FRANCISCO -- Giants second baseman Freddy Sanchez underwent successful surgery to repair his right labrum in Arizona on Tuesday, Giants manager Bruce Bochy said.

"From what we hear, the surgery went well," Bochy said. "They repaired the labrum, and he should be ready for Spring Training."

The operation brings a definitive end to Sanchez's 2011 season. The second baseman played 60 games, batting .289 with a .730 OPS (on-base plus slugging percentage). Head athletic trainer Dave Groeschner had previously said Sanchez would need a few weeks to let the injured area "calm down" following surgery. He injured the shoulder diving for a ground ball June 10 and attempted to rehab it before opting to surgically repair it.

Sanchez has dealt with a number of injuries during his time with the Giants. He underwent surgery on his left shoulder twice in a year, most recently in December -- a procedure that slowed him in Spring Training this year.

Bochy will play hot hand, matchups in center

SAN FRANCISCO -- Cody Ross blasted a leadoff home run Monday, finishing the night 2-for-4 and playing well in center field, but that doesn't mean the Giants are done mixing and matching at the leadoff spot.

Ross was once again hitting atop the order and roaming center field Tuesday night against the D-backs, but Giants manager Bruce Bochy said he will still rotate Ross, Aaron Rowand and Andres Torres at the position. Bochy said Carlos Beltran would be in right field every day, and Nate Schierholtz would get the "lion's share" of starts in left. That leaves only one spot for the remaining three outfielders.

"We're going to look at matchups, how they're swinging -- all those things come into play as far as who's going to play center field," Bochy said. "I see Cody as a very good candidate to get time out there along with Aaron and Torres."

Given Torres' yearlong struggles after a sensational 2010 season, Ross would appear to be the most well-rounded candidate to receive consistent starts in center. Rowand and Torres could conceivably split time, given Rowand's unimpressive .214 clip against right-handers this year and Torres' paltry .114 average against lefties.

Upon Beltran's arrival, Ross appeared likely to join a left-field platoon with Schierholtz. Bochy even said Monday it's not out of the question that Schierholtz could quickly learn to play center field and get time there. Until someone steps up and claims the leadoff spot, however, the versatility of Ross, Rowand and Torres will allow Bochy to tinker with the lineup as he and his coaching staff see fit.

"It's nice to have three guys who can play center field. It does give you that option of putting a guy out there who you think gives you the best matchup," Bochy said. "We're just looking for consistent, quality at-bats. These are things we talk about on a daily basis with who plays out there. The easy thing would be to say, 'This guy's going to be out there every day.' But then you're leaving two guys out who are very good players, and they're used to being out there every day."

Bullpen doing good work, and lots of it

SAN FRANCISCO -- The Giants' bullpen is matching its efficiency with frequency.

Jeremy Affeldt, Javier Lopez, Brian Wilson and Sergio Romo are on pace to finish the regular season with more than 70 appearances apiece. At the current rate, Affeldt would accumulate 79 outings, Lopez 77, Wilson 76 and Romo 74.

The only other year in the franchise's San Francisco history that four Giants relievers each amassed at least 70 appearances was 1997 (Julian Tavarez 89, Doug Henry 75, Rod Beck 73, Rich Rodriguez 71).

Like this year's team, the 1997 club excelled in close games. Those Giants compiled the Major Leagues' best record in one- and two-run decisions (43-28, .606).

"Usually if you're putting that type of work in, most of the time that's a good sign, you know what I'm saying?" Affeldt said Tuesday.

San Francisco entered Tuesday trailing San Diego for the league's lowest ERA by an infinitesimal amount, 2.8304 to 2.8252. Also before Tuesday, Giants relievers had allowed zero earned runs in 17 innings at AT&T Park while limiting opponents to a .020 batting average (1-for-51).

By now, it has become obvious that the Giants' bullpen is extremely balanced. Guillermo Mota, who usually fills the long relief role, is the only member of the bullpen with an ERA exceeding 3.00.

"If I'm having a rough day, how many guys can back me up?" Romo asked rhetorically.