Dallas, TX (My Sportsbook) - The Dallas Mavericks suffered a huge blow on Monday, as guard Nick Van Exel underwent arthroscopic surgery on his right knee. Van Exel will miss the next three to six weeks.

The 30-year-old Cincinnati product told the team about the discomfort and had the unexpected surgery. Mavericks coaches urged Van Exel to undergo the procedure immediately instead of trying to play through the pain.

Van Exel averaged just 20.2 minutes in the first six games and managed just 9.5 points and 3.3 assists. He is shooting 37.5 percent from the floor.

Last season, Dallas acquired Van Exel, forward Raef LaFrentz and guards Tariq Abdul-Wahad and Avery Johnson from Denver. The Mavericks sent forwards Juwan Howard and Donnell Harvey, guard Tim Hardaway, a 2002 first round pick and $1 million to the Nuggets.

LaFrentz, who suffered an ankle sprain in the third game of the season, is also out for some time. LaFrentz was injured during the third quarter of a 97-83 win over the Phoenix Suns. LaFrentz is averaging 10.0 points and 3.5 rebounds per contest this season.

Johnson will fill in for Van Exel as the backup point guard to Steve Nash.

Dallas is the only undefeated team in the NBA with a 6-0 record.