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09/14/11 8:57 PM ET

Ethier undergoes successful knee surgery

LOS ANGELES -- Dodgers right fielder Andre Ethier underwent successful surgery on his right kneecap Wednesday morning.

Dr. Neal ElAttrache performed the surgery, which was a 35-minute arthroscopic procedure to clean up the wear and tear behind the kneecap.

Ethier's rehab will take six to eight weeks and will start within the next week.

An All-Star this season, Ethier's numbers began to decline after the break, and he played his last game on Sept. 6. He finished the season hitting .292 with 11 home runs, his lowest total since 2006.

"No complications once they got in there," manager Don Mattingly said. "They didn't have to do anything that would have had to push the rehab into a longer period of time. So that went really well."

Sands learning to relax in second stint in LA

LOS ANGELES -- Jerry Sands didn't need to make any adjustments to his swing or his approach.

All the Dodgers rookie outfielder needed was for a hit or two to sneak through. Well, they started sneaking through Monday, and by Tuesday those hits were already line drives.

"A few hits fall in here and there, and you can relax a little bit and take a few deep breaths," Sands said.

After just one hit in his first 14 at-bats since being called up, Sands now has five in his last six. On Tuesday, he was 2-for-2 and worked a pair of tough walks. His first-inning double off National League Cy Young candidate Ian Kennedy of the D-backs came on a 1-2 pitch.

Sands struggled in his first stint with the club earlier in the season, and he noted he was trying to avoid falling into a similar slump.

"More than anything, it's kind of just mental," Sands said. "I was just coming up here to try and not fail again, so I was trying to do too much, coming off my legs. I just had to slow down and relax a little bit."

Manager Don Mattingly said he's already noticing Sands feeling more comfortable.

"He looks like he's starting to relax a little bit," Mattingly said. "Hits always help. You get a couple hits you just feel better, and that's what you're looking for with Jerry and all the young guys, you want them to take that breath."

Mattingly has started Sands in each of the last six games and he gave him the start again on Wednesday. He noted Sands would see some time at first base as the season winds down and said he plans to keep using the highly touted prospect on a daily basis.

"Sometimes it's probably good for them to get a little tired and battle when they're not all jacked up, when they can just relax and play," Mattingly said.

Sands wouldn't want it any other way.

"One at-bat a day and one at-bat every couple days makes it pretty tough to get a rhythm," Sands said. "Pinch-hitting is a lot harder than it seems. Playing on a daily basis, getting three, four, five at-bats a day is big. You get rhythm, you get timing."

Mattingly says Guerra can learn from first loss

LOS ANGELES -- The word Dodgers manager Don Mattingly kept coming back to Tuesday night when referencing his rookie closer's sudden and stunning demise was "uncharacteristic."

After Javy Guerra had suddenly lost the strike zone and walked three straight batters to allow the winning run to score, Mattingly said as much with a grim tone. A day later, he was already seeing the loss in a different light.

"In the long run, it's something that's good for Javy," said Mattingly, who also noted that Guerra wouldn't be available for Wednesday's series finale against Arizona. "You hate to say it because it cost you a game, but all the stuff that happens to these guys, the good stuff and the bad, is experience that you learn from."

Guerra has been dominant for most of the season. He has converted 18 of his 19 save opportunities and until Tuesday hadn't recorded a loss and had an ERA under 2.00.

Sure, the 10-inning loss irked Mattingly, but he noted that the club's focus for September is a little different because it is out of the pennant race.

"What you're looking at at this point in the season for us, is you're looking for development, and you're looking to see how guys are going to react, and you're looking to give guys experience, so when you get in that situation again, they've been there before," Mattingly said.

AJ Cassavell is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.