The Seahawks added center Chris Spencer to the injury report on Saturday because he is suffering from a bad back.
Steve Vallos actually was getting reps in practice on Friday, which led to some questions about whether he and Spencer were going to split time during tomorrow's game. Mike Holmgren laughed and said he didn't even realize Vallos had been taking snaps. Now we know why.
Spencer missed a bunch of time during training camp because of the back, though it has not bothered him since, at least not that we have been told. This may not be the worst thing, though, because it could give the coaches an idea of what Vallos can do in a regular-season game.