An early indicator

Lovie Smith doesn't hesitate to call the current defense the best he has had in four years as Bears head coach.

That group gets an early opportunity to prove it today against a San Diego Chargers team that was the highest-scoring NFL unit in 2006.

"For the most part, our core is still intact and we've added some good football players to the mix," Smith said. "We definitely, to a man, will say we can take another step defensively, and we'll get an early look at exactly how far we are, how far we have gone, and where we need to go from there."

The Bears were the NFL's best defense last season through 12 games, but the loss of safety Mike Brown (Week 6) and defensive tackle Tommie Harris (Week 12) hurt the team's final numbers.

Both Pro Bowl players are back. The Bears also believe they have strengthened the secondary by adding strong safety Adam Archuleta, and improved the line by replacing tackles Tank Johnson, Ian Scott and Alfonso Boone with Dusty Dvoracek, Darwin Walker and Anthony Adams.

"I guess we're going to find out," Archuleta said of the hype. "We've had a great off-season, training camp and preseason. We've passed all those tests. But we can't rest on what we've done in the last month; we have to play well this week. Our identity's going to hinge on this game and what kind of momentum we have going through the season."

The 2007 group will have to jell quickly, stay healthy and overcome a tougher schedule to overshadow last year's defense, which, despite fading at the end, still finished No. 5 in yards allowed and No. 3 in points allowed.

"It's a lot to live up to," said defensive coordinator Bob Babich, who was promoted from linebackers coach to replace Ron Rivera after last season. "The previous two years we've had very good defenses statistically.

"Leading the NFL in takeaways is a big part of what we do, so obviously to better that, we've got to have a great year. But with the depth and the experience we have, we're excited about the opportunities ahead of us."

The Bears led the NFL with 44 takeaways last season, but the Chargers turned the ball over less than anyone in the NFL, just 15 times, 21 fewer than the Bears.

Offensively, San Diego was No. 2 in rushing yards and No. 4 in total yards and average gain per rushing play.

"It's as good an offense as we're going to face," Babich said. "It's a great opportunity. I think it's going to help us and show us where we're at."

While Harris is back and expected to start, it remains to be seen how close he will be to the player who began last season with 5 sacks in the first four games. He played so dominant early that he was voted to his second straight Pro Bowl despite missing the final four games because of the hamstring injury that required surgery and a lengthy rehab.

Harris played just seven snaps in the preseason, but Smith is confident he will be a factor today.

"He's practiced full speed," Smith said. "Tommie is ready to go. Right now Tommie is worried about getting penetration, getting up the field, and trying to cause havoc."

Harris admits he must overcome the mental hang-ups of his first serious injury. But he expects to do that today, and he insists stamina won't be a problem, although he isn't expected to play as many snaps as usual.

Smith also downplays the stamina factor.

"You can say that about all of our team," Smith said. "We haven't played a full game. They're in the same situation. I would like to think that's going to hurt L.T. a little bit, since he hasn't played any.

"But once you get there and you're in decent shape, you find a way to play at a high level throughout the game."

Anything less from the Bears' defense could mean TD for L.T. (LaDainian Tomlinson), who set an NFL record with 31 scores in last season's MVP campaign, which included 1,815 rushing yards. As usual, Tomlinson did not play in the preseason, because he doesn't need to.

"We know what he's able to do in this league. It speaks for itself," Archuleta said. "You just have to go out there and play swarming defense and not let him breathe. He's got the ability to beat you, so we're going to have to be on top of our game."

That's a must for a defense that wants to be at the top of the NFL.