Patriots DE Jarvis Green underwent arthroscopic knee surgery to repair a meniscus injury last week, according to a league source.
The decision to have surgery was made based on having Green ready for the season's stretch run. By having it done now, the Patriots will likely have Green back by early December.
Green already has started all seven games this season at defensive end. He's in the final year of a five-year contract he signed prior to the 2005 season.
Update (10:59 a.m.): A source put the timetable for Green's return at 2-4 weeks. While he's likely out for this week's game against the Dolphins, the possibility exists he could play in Indianapolis against the Colts.
Green is already walking on the surgically-repaired knee.