LAKE FOREST, Ill. -- The dress rehearsal looked more like a rerun for the Chicago Bears.

While the 34-6 preseason loss Friday to the Seattle Seahawks certainly put on display the world champions' prowess, it brought to the surface numerous Bears flaws. Many of these, particularly on defense, dated back to last year and made it seem as if little has changed despite a few different faces.

"We didn't play well enough to make it a competitive game in any phase of our football," coach Marc Trestman said. "I think we've got to take it all in perspective and I think our team does. I think we're humble enough to know that we've got work to do, that what we saw out there is correctable. But we've got to clean up our football in all three phases."

However, it starts with their defense, the biggest problem from last year. The Bears' defense couldn't get off the field unless it was with the officials' arms upraised.

Seattle drove 69, 81 and 63 yards for scores, then converted a 59-yard punt return into a 16-yard drive. They tossed in a 59-yard field goal just before halftime after quarterback Jay Cutler threw an interception to make it 5-for-5 scoring against the Bears defense, going 7-for-7 in third-down efficiency in the process.

It wasn't just the Seattle precision, but the way the defense surrendered yardage that bodes poorly for the Bears.

They have been working extensively at defending the read-option game Seattle runs throughout practices dating back to the start of OTAs. They've spent an inordinate amount of time working on their run fits against this offense, and on keeping quarterbacks within the pocket. Then they proved entirely ineffective keeping quarterback Russell Wilson contained.

The problems did occur with defensive end Jared Allen missing the game with a bruised shoulder, but when he did play against Jacksonville the Bears experienced a similar problem keeping quarterbacks in the pocket.

"The stats are what they are," Trestman said. "You've got to get off the field on third down. And you've got to also try to get in a position where they're not third-and-manageable, which makes, obviously, a much better percentage for them to convert.

"But (Seahawks quarterback) Russell (Wilson) did what he was tremendous at. He was able to get out of the pocket, find guys up the field or extend plays with his feet and his legs. And he did all that tonight. He was certainly in midseason form."

When the regular season begins, the Bears face the Bills, 49ers and Jets, followed by a game against mobile Aaron Rodgers and the Packers and then Cam Newton and the Panthers. They're going to have to get used to chasing elusive quarterbacks in the read-option.

"This is going to be a very good learning tape for us because, as I said, we face in the first three games mobile quarterbacks who are going to run read-zone, who are going to try to go outside the pocket, who are going to ty to extend plays with their legs," Trestman said.

The underlying fear with the Bears defense it has not done enough to get younger, faster, and better able to cope with mobile quarterbacks. Its linebacker corps remains anchored by 30-somethings Lance Briggs and D.J. Williams. While defensive end Willie Young enjoyed a good night statistically as Allen's fill-in with six tackles, a sack, a tackle for loss and a couple quarterback hits, Seattle found ways to get outside and the run defense surrendered 85 yards in the first half.

The one defensive highlight the Bears came away with was Chris Conte's return from shoulder surgery showed they may have a second safety on their roster to team with Ryan Mundy. Conte delivered a big hit to break up a pass in the end zone, scored another big hit in the run game. And then he wound up on the bench with a concussion.

So much for the positive.

The offense lost starting fullback Tony Fiammetta to a pulled hamstring -- a player they have no substitute for on their roster -- and special teams still hasn't found a return man or a way to stop a return. Certainly the defense wouldn't have looked so flawed if the offense provided some points while moving the ball for 163 yards with a turnover and missed field goal to show for it.

Ultimately, the defense has to get off the field and didn't, and it's a problem very similar to last year.

The Bears will get one more brief chance to prove Thursday they can handle mobile quarterbacks against the Cleveland Browns, before the regular season begins.

"I think we've got to take it all in perspective and I think our team does," Trestman said. "I think we're humble enough to know that we've got work to do, that what we saw out there is correctable.

"But we've got to clean up our football in all three phases. We've got to clean it up from this game."