TUKWILA, Wash. (AP) - Star Seattle Sounders defender Chad Marshall will miss the second leg of the MLS Western Conference semifinals because of knee surgery.

Coach Brian Schmetzer says the center back was having surgery Tuesday to repair cartilage in his right knee. There was no word on how long the anchor of Seattle's defense will be out.

Marshall injured his meniscus during Seattle's 2-1 loss to Portland in the first leg Sunday and was replaced in the 40th minute.

Marshall is a finalist for MLS defender of the year along with Aaron Long of the New York Red Bulls and Atlanta's Michael Parkhurst. Marshall has won the award three times.

Midfielder Cristian Roldan will be a game time decision. He has a hip flexor.