Change is in the air for the Bears

Shea McClellin's conversion from end to linebacker has received an inordinate amount of attention during the off-season. But that's just one of many changes being implemented on a Bears defense anxious to distance itself from last year's debacle.

It starts with attitude and the desire to prove that last year's embarassment was an aberration.

"It's a big chip (on your shoulder) because that's not Chicago football," cornerback Tim Jennings said. Jennings made it to the Pro Bowl for the second straight season in 2013 despite playing on a unit that allowed the most points in franchise history.

"It's not what we're known for, regardless of who was here and who we didn't have," Jennings said, alluding to injuries that hit hard, especially along the defensive line. "That's just having pride in being a part of this defense, being a part of this team. ...

"Everybody has that chip on their shoulder, to get that taste out of their mouth, to get back to Bears football."

The Bears were the worst of all 32 NFL teams when it came to stopping the run in 2013 and also in yards per play allowed. They tied for 30th in points allowed, were No. 30 in total yards allowed, No. 27 in average gain per pass allowed and 26th in sack percentage.

"We have a long way to go," linebacker Lance Briggs. "There are a lot of things that we're going to have to correct this year. Tackling was really bad. Everything we did was almost all atrocious."

'It's very natural'

McClellin's move to strong-side linebacker should help a pass rush that lost leading sacker, Julius Peppers, in free agency. McClellin tied for second on the team last season with 4 sacks, the same total as last year's strong-side linebacker James Anderson, who was also allowed to leave in free agency.

Because McClellin, the Bears' first-round pick in 2012, split his time between defensive end and linebacker at Boise State, the Bears are confident he'll be able to make a fairly smooth conversion to his new poisition.

"It's very natural," said McClellin, who has cut his weight from 260 to 245. "The instincts are there, and I've just got to work on the concepts. My first two years weren't the greatest, but I think linebacker is a natural fit for me. I think it's what I should be doing, and I'm very excited about it."

In learning the responsibilities of his new position, McClellin says he can lean on Briggs and his 11 years' experience at the position. Briggs says McClellin should be fine - eventually.

"Shea is an athlete," Briggs said. "He's smart. (But) just like anybody else, when you're new at something, it's going to take some time. You've got to keep working at it.

"But he's fine. He's going to do well. He's a very transitional guy. He can play everywhere. Shea is going to help us."

Jennings on the move

Because the Bears believe first-round cornerback Kyle Fuller is also going to help, the plan is for incumbent left cornerback Tim Jenning to move inside to nickel back in passing situations so Fuller can temporarilty take his spot at left corner.

"We're gonna try it out," Jennings said. "It's new to me, (but) I played nickel earlier in my career when I was at Indianapolis. It's just going to take a little bit of an adjustment for me. (But) it's all the same playing corner."

Jennings understates the challenge. Nickel is a more complicated position than corner, and it requires a special skill set.

"It's a little different," Jennings admitted. "You're just another linebacker; an athletic linebacker. It's a lot more reads, a lot more keys, that you have to get. I've got to get used to seeing different people, different formations."

4-3 still the base

Defensive coordinator Mel Tucker stuck with the 4-3 scheme last year that the Bears have always played in the past. But he has also coordinated 3-4 defenses, and the Bears are expected to display some scheme diversity this year. Tucker wanted to experiment more last season, but the D-line injuries torpedoed that plan.

That shouldn't be a problem this year. Even though Corey Wootton also departed via free agency, leaving the Bears without both starters, they were replaced by a trio of free agents. The addition of Lamarr Houston, Jared Allen and Willie Young should more than offset the losses.

Despite the new personnel and plans for some experimentation, the 4-3 will still be the Bears' base defense, and Briggs doesn't expect his assignments to change much.

"It's still going to come down to running to the ball, making plays, getting the guy down and get the ball away from him," Briggs said. "I'll be a traditional Will (weak-side linebacker). We're going to go, 'See ball,' and I'm going to go hit ball.

"We're still running a 4-3. There are some differences, but most of it is very similar or much the same."

Safety dance?

The safety position could be very much different this season. Major Wright, the starting strong safety for the previous three seasons, joined the Bucs in free agency. Chris Conte, the starting free safety for the previous 2½ seasons, is coming off shoulder surgery after a forgettable 2013 season.

To upgrade arguably the most disappointing position on a poor defense, the Bears brought in former Packer M.D. Jennings, ex-Giant Ryan Mundy and Danny McCray (Cowboys) in free agency and drafted Minnesota's Brock Vereen in the fourth round.

Because Conte may not be 100 percent healthy until at least the end of training camp, and because he's coming off his worst season, it's possible the Bears will have two new starting safeties on opening day.

Jennings, who started all 16 games for the Packers last season and 10 games the year before, is taking it one step at a time.

"Every time I go to camp, my main focus is first to be on the 53-man roster," the 25-year-old said. "Then worry about starting and stuff like that later."

• Follow Bob's Bears and NFL reports on Twitter@BobLeGere.