If everything goes according to schedule, the 34-year-old Nowitzki will miss about a dozen games starting with his team's October 30 season-opener versus the Los Angeles Lakers.
The German, the only European to win the NBA's Most Valuable Player award, started having troubles with his right knee before last season.
He had the knee drained twice in the past month to reduce swelling and soreness, but the problem reappeared both times.
Nowitzki had hoped to delay the operation but team doctors said it was better to get it done sooner.
- Los Angeles Lakers