RENTON, Wash. — It was only fitting that the power was out for about half an hour Monday afternoon at Seahawks headquarters.

It's been that kind of season for the Seahawks — lacking electricity and full of bad luck.

The misfortune continues, as the news on quarterback Matt Hasselbeck's injury situation got worse. It isn't so much a sore right knee as it is a bulging disk in his back that Hasselbeck was diagnosed with before the regular season began.

The back problem is affecting a nerve in Hasselbeck's lower back, coach Mike Holmgren said, and is also creating a weakness in Hasselbeck's leg that brought on the knee injury. Hasselbeck left for Los Angeles to see a medical specialist after Sunday's loss to the Green Bay Packers and was there Monday.

"It appears as though he will not be able play this week," Holmgren said of Hasselbeck. "They put him on a series of rehab tests . .. and as soon as he can pass those as far as strength in his leg, then we can get him back on the field."

The team hopes to have Hasselbeck back for the game at San Francisco Oct. 26. Seattle's next game is at Tampa Bay this Sunday.

Seneca Wallace, Hasselbeck's backup, could start at Tampa Bay depending on how he performs at practice this week. Wallace is dealing with a sore calf and would have played only if No. 3 quarterback Charlie Frye got hurt against Green Bay. Frye played the entire game, and will get the call again if Hasselbeck and Wallace are ruled out.

Wallace went 2-2 as a starter in 2006, when he stepped in for an injured Hasselbeck. The last game he missed was Nov. 19, 2006.

Hasselbeck twisted his back awkwardly while avoiding a hit and throwing a touchdown pass in the exhibition opener on Aug. 8 at Minnesota, and missed the entire exhibition season while he dealt with back spasms. His bulging disk was diagnosed and treated with injections and he opened the regular season as the starter, but he hurt his knee after a hit early in the Seahawks' loss to the New York Giants on Oct. 5.

Hasselbeck, now in his 10th year, missed the entire week of practice leading up to the Green Bay game and was not active for the game. He watched from the sideline at Qwest Field, and after the game Holmgren said he was a little puzzled by the nature of Hasselbeck's knee injury.

"The fact is, right now they're dealing with his back more than his knee," Holmgren said. "It's pressing against the nerve and they have to quiet it down."

Holmgren was asked to clarify how the back and knee injuries were related.

"All I know from my own experience, if you hurt something, a knee, anything, a foot, and then all of a sudden you start to favor that and you don't even know you're doing it," Holmgren said. "It can create other things that happen with you."

Holmgren had some parting words for Hasselbeck as the quarterback prepared to leave for Los Angeles.

"I just wished him luck," Holmgren said. "I was encouraged by the fact that maybe we could find out what's going on. I was nervous that it might be more time lost . . . its better than it could have been, I suppose."