Now, it's leading receiver Darrell Jackson.

Seahawks coach Mike Holmgren said Monday that Jackson will not be able to play Thursday night against San Francisco, another blow for Seattle's injury-riddled offence.

Jackson has turf toe, suffered on his last reception in Sunday's 27-21 loss at Arizona. Jackson caught a 23-yard pass from Hasselbeck with 3:15 left, but didn't return for the rest of the drive.

Holmgren had no timetable for when Jackson, Seattle's leader with 63 catches for 956 yards and a league-high 10 receiving touchdowns, might return. Nate Burleson, a Calgary native, will start for Jackson.

``Last year we were pretty fortunate,'' Holmgren said. ``It happens, and you do what you have to do to plug the holes.''

Jackson wasn't the only major injury. Defensive tackle Craig Terrill will be placed on injured reserve after injuring ligaments in his knee. Terrill is the second defensive tackle to be placed on injured reserve, joining Marcus Tubbs, who was lost for the season with a left knee injury.

Seattle is fortunate to be deep along the defensive line. Robert Pollard will be added from the practice squad to the four-man rotation at the two tackle positions that includes Russell Davis, Chuck Darby and Rocky Bernard.

``Fortunately we had a couple of extra people there to start with, or else we would be in a world of hurt right now,'' Holmgren said. ``We can still line up people and play, but we have taken a couple of hits in there.''

Oft-injured left guard Floyd (Pork Chop) Womack also is a question mark with a nagging groin injury. Holmgren said if the Seahawks had a normal week and were playing Sunday, Womack might be able to go. But with the game Thursday, Holmgren classified Womack as ``iffy.'' If Womack can't go, rookie Rob Sims would start at guard.

Womack missed five games earlier this season with a knee injury.

Holmgren is hopeful Bobby Engram might be able to play. Engram has not played since Week 4 at Chicago, sidelined with a thyroid problem. Holmgren said he hasn't talked with the veteran receiver about if he feels well enough to play.

``We're going to try and fast forward so that Bobby can play a little bit on Thursday night. That's my hope,'' Holmgren said.