Change is inevitable for the Bears as they transition to new head coach Marc Trestman after nine years under Lovie Smith.
But the 2013 defense should have a familiar look to it.
"It will be very similar to what we have had here," Trestman said Thursday afternoon at an under-construction Halas Hall. "We're not going to change the style of defense that we're playing."
New defensive coordinator Mel Tucker has no intention of switching from the 4-3 alignment the Bears played under Smith, even though he has had experience in 3-4 schemes as well.
And why change? Tucker takes over a crew that was No. 3 in points allowed last season, No. 5 in yards allowed, No. 2 in interceptions and No. 6 in third-down efficiency.
The pass rush, which was up and down over the Smith years, while relying mostly on the front four to get pressure, might be more diverse under Tucker, the Jacksonville Jaguars' defensive coordinator the previous five seasons.
"It's got to come from everywhere," Tucker said of the pass-rush pressure. "We've got to get pressure on the quarterback. It could be (with) four, it could be five, it could be six. It could be three. It's a deal where rush and coverage have to work together. We've got to get there.
"We want to hit the ground running. This time of year, just like every other team in the NFL, you're trying to find a way to get better. That's what we're doing right now. We're just moving forward."
That will be easier if unrestricted free agents Henry Melton, Brian Urlacher and Israel Idonije are back. Trestman and his staff have only just begun to evaluate personnel while also planning for the start of free agency March 12 and preparing for the draft, which begins April 25.
Urlacher will be 35 before next season starts, but his departure would leave a gaping hole at middle linebacker. It's an easier decision to open the checkbook for defensive tackle Melton, who is just approaching his prime and coming off his first Pro Bowl season.
But Urlacher has been the face of the franchise for a decade and, although his play has declined, there is no apparent heir.
Urlacher cannot command the $7 million salary he made last season, but his knowledge and experience are priceless and would make the transition from Rod Marinelli to Tucker more seamless.
Trestman has yet to meet with Urlacher in person. They recently spoke at length on the phone, but no decisions have been made as to Urlacher's future in Chicago.
"I'm excited to come here because Brian Urlacher has been such an important part of this," Trestman said. "But to talk about where that thing is going would be premature at this time.
"We just talked generally about the team, not specifically about his situation. I'm not as attuned to the entire situation, certainly the economics. That's going to be a process between Brian and the organization as we move forward."
The defense will have a good degree of continuity on the coaching staff. Defensive backs coach Jon Hoke and defensive line coach Mike Phair were the only ones retained from Smith's staff.
"We're going to call things generally the same way," Trestman said, "and put some spin on it that Mel can bring with him from where he's been in the past. But essentially the style of football that we're going to play defensively will not change much.
"We talked to our players about that, and I think they're excited about the fact that we can continue to play the Bears' defense that we've been accustomed to playing here over the years."
Bringing even more familiarity to the defensive staff is former safety Chris Harris. The recently retired Harris had two two-year stints with the Bears as a player and is starting his new career as a defensive quality-control coach.
"Chris is highly intelligent," Tucker said. "I had him for a little bit in Jacksonville. He picked up our scheme very quickly. He's familiar with the players and the scheme, so he'll do a great job coaching our guys."