The MRI results are back and Seahawks QB Matt Hasselbeck does have an injured medial-collateral ligament in his right knee. He could be out for about a month. Right now the Seahawks can probably expect Hasselbeck to return for the San Francisco (11/19) or Green Bay (11/27) games.
Every individual is different, so we don't want to rule out an earlier return. But remember when Mike Holmgren suggested Shaun Alexander might miss a couple weeks? They seem to err on the side of caution, which makes sense when you are dealing with franchise players such as Hasselbeck and Alexander. I'll be a little surprised if Seneca Wallace isn't the quarterback for the next three games or so.