RENTON, Wash. — Seahawks quarterback Matt Hasselbeck will miss his fourth consecutive week because his hyperextended right knee is still weak, but coach Mike Holmgren said he sees "light at the end of the tunnel."

Holmgren confirmed Wednesday that backup Seneca Wallace will make his third consecutive start on Sunday when Seattle (2-5) hosts Philadelphia (4-3).

"We don't know how long he's going to have (to play)," Holmgren said. "He's our quarterback right now."

This week, Dr. Robert Watkins, a noted back surgeon in Los Angeles, said a bulging disk in Hasselbeck's back is still weakening his knee. The three-time Pro Bowler has said he will have to make at least a third trip to Watkins for more tests before he can return.

"As far as I can tell he's making progress. His leg is a little stronger. So to me there was some light at the end of the tunnel there," Holmgren said. "Hopefully, with all the stuff he's doing, we can get him back on the field at some point. But, again, that will be on a week-to-week basis."

Wallace drastically improved last week while leading the Seahawks to their first win in five weeks at San Francisco. Wallace completed 12 of 23 passes for just 73 yards in his first start since 2006 against Tampa Bay on Oct. 19.

Holmgren said wide receiver Deion Branch also will miss Sunday's game because of a bruised heel that has the Seahawks "essentially shutting him down" this week. Branch has played in one game since January following reconstructive knee surgery.

Pro Bowl defensive end Patrick Kerney is iffy after re-injuring his left shoulder after having offseason surgery to repair a torn labrum. Holmgren said Kerney likely won't practice this week but is still holding out hope his top pass rusher can chase Donovan McNabb on Sunday.

"There is a little bit of a concern," Holmgren said. "In talking with Patrick today, he's somewhat concerned."

Lofa Tatupu won't practice much, if at all, because of a groin injury, but Holmgren said the Pro Bowl linebacker will play on Sunday.