MILWAUKEE -- The Pirates' medical staff has advised outfielder Brandon Moss that he needs surgery on his left knee to address a lack of cartilage, a procedure that would keep him out 4-6 months. But Moss is seeking a second opinion later this week and hopes to avoid it.

In fact, he sounds determined to avoid it.

"I'll take into account what they say," Moss said yesterday, less than 24 hours after being informed. "But I know my body, and I know I feel fine."

Regardless, Moss will not play in the season's final four games.

The lack of cartilage in the knee is causing two bones to rub together and creating a small divot, but Moss was adamant that he has experienced no pain since joining the Pirates, declaring himself "100 percent." The most recent pain, he said, came in June while with the Boston Red Sox when he would play on artificial turf. Since the July 31 trade, the only pain has come in walking on steps.

There is no ligament damage.

The issue was uncovered in a routine end-of-season examination by Dr. Patrick DeMeo, the team physician, through an MRI after Moss informed the team of the knee's history.

Moss' next step will be to fly back to Pittsburgh today for another checkup with DeMeo. Then, Thursday or Friday, he will see Dr. John Steadman, a noted knee specialist, in Vail, Colo., at some point in the next couple of days. Dr. Steadman, the surgeon who operated on former Pirates outfielder Jody Gerut's knee two years ago, is scheduled -- for now -- to perform only an examination on Moss.

If the surgery being advised is performed, it will create tiny holes in the rubbing bones with an aim of regenerating the cartilage there.

Moss and Pirates manager John Russell each dismissed the knee as a possible factor in Moss hitting only .222 -- with six home runs and 23 RBIs in 158 at-bats -- since his acquisition.

"He has such a violent swing that you'd think you'd have seen him cringe or something in all that time," Russell said. "Never happened."

"Not a factor at all," Moss said. "It's just that it was only 150 at-bats. In another 150 at-bats, you can go out there and hit .390."

• First baseman Adam LaRoche was held out because of the tight left hamstring that caused him to get pulled from the game Sunday. LaRoche said that hamstring has troubled him on and off for two years. He could return as early as tonight.

• Milwaukee manager Dale Sveum waited until late yesterday afternoon that CC Sabathia will pitch tonight, his second consecutive start on three days' rest. This way, if the Brewers have their season on the line Sunday, Sabathia could start that one, too.

• In Moss' absence, expect Steve Pearce to get most of the starts in right field.