By Bill Swartz

"Disappointing" is the word Seahawks defensive coordinator Gus Bradley used to describe the run defense which allowed 189 yards in the loss to Miami on Sunday.

Bradley said several players, even some veterans, forgot their assignments.

"We run eight-man fronts designed to stop the run, so when they got some big plays against us, that was disappointing," Bradley said after Thursday's practice. "It wasn't any new concepts, it was just a lack of trust, and some guys trying to do too much at one time."

The Chicago Bears use running back Matt Forte on toss sweeps and screen plays very effectively, according to Bradley. They also have a larger back, Michael Bush, for the power plays.

Seattle's secondary will have its work cut out covering the Bears' primary receiver, Brandon Marshall. Bradley said the fact Seattle has faced Calvin Johnson of the Lions and Arizona's Larry Fitzgerald should help them against Marshall.

The Bears' patched-up offensive line is not asked to pass protect very long. Bradley says they run more quick plays which makes it difficult for the defense to get pressure on Jay Cutler, who can also extend plays with unusual side-arm and underhand shovel throws.

Alan Branch is getting the bulk of the work at defensive end as Red Bryant missed a second straight practice with a foot injury. Linebacker Leroy Hill has a sore ankle and was also held out a second day in a row.

The Seahawks won't have to face one of the NFL's all-time great kick return men Sunday. Devin Hester has been ruled out of the game with a concussion. Former Seahawks offensive lineman Chris Spencer won't play for Chicago either due a knee injury.

Forte, linebacker Lance Briggs and cornerback Charles Tillman are all dealing with ankle injuries but did make it through limited participation in Thursday's practice.