The Tribune's Rich Campbell and Dan Wiederer discuss the Bears defense from minicamp practice on Wednesday.

Brock Vereen will be the first to tell you he's still a rookie and that he barely has been through four weeks of offseason practices in his NFL career. So he knows his assessments may not carry grand weight.

But the Bears safety can say with conviction that he's enjoying the defense he has been brought in to help, energized by the system coordinator Mel Tucker has installed.

"Mel's on it all the time. He's involved," said Vereen, who has been mixing in with the first unit defense during minicamp this week. "Guys are working with an edge right now. It's cool. And it's because this defense is fun. We're active. And we're going to be have a lot of different looks."

The rookie's sentiments take on added meaning when you consider Jared Allen echoes them.

"There's an energy with this defense," the five-time Pro Bowler entering his 11th season with his third team said Wednesday. "Honestly, they're already getting more out of me than I ever anticipated. I haven't done this much in OTAs and minicamp in years.

"The pace is good. The vision is there. It's what you look for."

The Bears will have their final practice of the three-day minicamp Thursday, then break until training camp begins in late July. They will do so with internal optimism building and a sense that key defensive progress is being made.

The foundation was laid in April as players and coaches became more familiar with one another. From there, the ability of Tucker and his defensive staff to integrate the defense appears to have gone smoothly.

"We've established ourselves between coaches and players on how we do things here," coach Marc Trestman said. "It's really going to help us get off to a fast start in training camp."

For Tucker, there has been a whole lot of new this spring.

New concepts. New players. New bonds. New roles.

On Thursday, the 11-man group that began team drills as the first-unit featured four first-year Bears (Vereen and Allen plus safety Ryan Mundy and defensive end Lamarr Houston); four other players who played half the season or less last year (cornerback Charles Tillman, defensive tackle Jeremiah Ratliff and linebackers Lance Briggs and D.J. Williams); and two others still adjusting to new roles as Shea McClellin continues his defensive end-to-linebacker move and Tim Jennings now is sliding inside as a cornerback in the nickel defense.

That certainly alters the landscape of last season's statistical implosion when the defense allowed a franchise record 6,313 yards and finished last in the NFL by a mile against the run (161.4 yards per game). It also has sent Tucker and Trestman on a messaging mission, peppering defensive players with constant rhetoric about becoming tougher and more physical.

"We weren't the tough team we wanted to be for a lot of different reasons (last year)," Trestman said. "We want to accentuate it this year."

From an X's and O's standpoint, Tucker is stressing the need for the defense to set a vertical edge against the run, to show "a violent shed" off blocks and to run to the football. He also has highlighted the need for the defensive line to establish the tone and on Wednesday labeled that bunch "a salty group."

"It's a compliment," he said. "You can ask them if they think it's a compliment or not. … We're putting a premium on toughness and being rugged and being stout and having tremendous anchor in our d-line and being able to control blockers."

Trestman knows there's a long road ahead during training camp to continue shaping and fortifying the defense. But he also believes that during organized team activities and minicamp that the communication that has been delivered is as important as the system itself.

"The mentality starts with how we sell it," Trestman said. "These guys care about football. They want to be great. And they know to win in this league you have to play with an edge.

"Salty helps as long as your fundamentals and techniques are right, you're fundamentally sound and you're structured. But tough guys without a system doesn't work very good. It all goes together."

dwiederer@tribune.com

Twitter @danwiederer