Rod Marinelli steps in as the third coordinator in three years for a defense that ranked No. 2 and No. 5 in the NFL in its division title seasons of 2006-06, but fell to 28th, 21st and 17th since.

Bob Babich was going to make a Super Bowl defense even better after the Bears grew tired of Ron Rivera clashing with the Cover-2 defense and talking openly of his ambitions to become a head coach.

That didn’t work.

Head coach Lovie Smith then took on the defensive play-calling duties himself.

That didn’t work, either.

Now Rod Marinelli steps in as the third coordinator in three years for a defense that ranked No. 2 and No. 5 in the NFL in its division title seasons of 2006-06, but fell to 28th, 21st and 17th since.

So what grand changes does Marinelli promise?

"Not drastic changes schematically. Just subtle changes," Marinelli said Thursday.

This is the second time Marinelli is being asked to help revive Chicago’s defense. The former Detroit Lions head coach was hired to fix Chicago’s defensive line last year. The Bears’ sacks did improve, from 28 to 35, but not enough.

And now he is being asked to improve the entire defense for the first time. Marinelli, long known as one of the NFL’s best defensive line coaches, helped Tampa Bay lead the NFL in sacks for a 10-year period. But this is his first season as a defensive coordinator.

Chicago linebackers and defensive backs speak as glowingly of Marinelli as the defensive linemen did last year.

"We knew he was fiery last year," linebacker Pisa Tinoisamoa said, "but now we’re getting that coaching from him every single day. He’s a good teacher. It’s easy to yell at guys to make your emphasis, but with Rod, we respect him because we know that he understands. He knows how to communicate with pros."

Safety Danieal Manning praised Marinelli’s passion and motivational skills.

"He believes in what he’s saying, and everybody else believes in it," Manning said. "Once you get on the same page, it’s hard to stop."

Marinelli’s defensive page is a simple one: be physical, pressure the passer and work together.

The Bears made only 13 interceptions last year, their fewest since they had nine in a disastrous 4-12 season in 2002. Marinelli has a simple formula for boosting that number.

"It’s rush and cover. And it’s believing in what you are doing," he said. "The big thing when you are playing team defense is trust. If they trust the ball is going to come out on time, guys will break on the ball correctly. So it’s the trust, the rush, the cover. It all goes together."

So for the old defensive line coach, coordinating a defense starts with coaxing a pass rush out of the line. Marinelli’s success is tied to new $91.5 million defensive end Julius Peppers and a bunch of unimpressive holdovers. Peppers is Chicago’s only lineman who had more than 3.5 sacks last year.

"The one thing we have to have in our system when you develop a four-man rush, is you gotta be able to pass rush," Marinelli said. "You have to.

"Not just third downs. First down, too. Play action is a good rush down for you. That is a key point for us. They’ve got to do it all, but the icing is the rush. We have to have that."

If not, the third new defensive coordinator will look a lot like the last two.

The Bears insist this time is different.

"Rod’s awesome," linebacker Lance Briggs said. "He’s a throwback. He’s an old-school guy. That’s right up my alley. He’s an in-your-face guy.

"What he wants from you, he demands from you. And he’s going to get it out of you. He’s going to get it out of all of us."

Rockford Register Star assistant sports editor Matt Trowbridge can be reached at: 815-987-1383 or mtrowbridge@rrstar.com.