RENTON, Wash. — Seattle Seahawks wide receiver Nate Burleson is out for the season because of a knee injury.

Burleson tore the anterior cruciate ligament in his left knee while trying to cut outside on a pass pattern on a rain-slicked field in Buffalo on Sunday during Seattle's 34-10 loss in its season opener.

Coach Mike Holmgren said his team will also again be without veteran receivers Deion Branch and Bobby Engram for this Sunday's game against San Francisco. Branch is seven months into recovery for reconstructive knee surgery similar to what Burleson now faces. Engram may be out into October with a broken shoulder.

Seattle has three healthy receivers on its roster. Holmgren says the team may sign a veteran free agent before practice on Wednesday.

Starting running back Maurice Morris will also miss at least the next two games with a sprained knee. Former Dallas lead runner Julius Jones will start against the 49ers.