Washington Nationals catcher Paul Lo Duca will be unavailable at the start of spring training after having arthroscopic surgery this morning to repair a partially torn medial meniscus in his left knee.

The surgery was performed by Dr. Ben Shaffer at Sibley Memorial Hospital in the District.

Lo Duca hurt the knee while working out in New York last week. Initial reports were that the injury was not too serious, but an MRI revealed a tear. He will begin a rehab program later this week and will miss four to six weeks of action.

Even if Lo Duca comes back quickly, he will miss at least the first two weeks of camp in Viera -- obviously not a good thing for a team entering spring training with a host of young pitchers.

The Nationals signed Lo Duca to a one-year, $5 million contract this offseason after trading Brian Schneider to the Mets as part of a deal for Lastings Milledge.

Lo Duca's injury ensures that he will be a hot subject in spring training. The catcher has not addressed the media since being named in a report by former Sen. George Mitchell that outlined the use of performance enhancing drugs in baseball.

-- Tim Lemke