LA Galaxy midfielder Clint Mathis will be sidelined from four to six weeks after undergoing surgery for a knee injury he sustained in training.

The 33-year old, who returned to the Galaxy in January, tore his meniscus in his left knee at training last week and had the operation on Friday.

Despite the setback, Mathis is expected to be fit and available for the Galaxy's 2010 MLS opener against New England Revolution on March 27.