Considering that offensive linemen make up about 17 percent of an NFL team's 53-man roster, their position coach is arguably the most important figure after the coordinators.

That makes the hiring of highly regarded Harry Hiestand as the Bears' offensive line coach one of the most important hires by head coach Matt Nagy. Hiestand coached the Bears' O-line from 2005-09, when the team went 47-33 under Lovie Smith.

Hiestand, 59, coached Notre Dame's offensive line the past six seasons, and two of his top pupils, guard Quenton Nelson and tackle Mike McGlinchey, could be drafted in the first 20 picks this year .

"Here's a guy that's a complete technician," Nagy said of Hiestand, who also spent eight years at Illinois (1997-2004). "You talk to anybody in college or the NFL, the amount of respect that he has as a coach and as a person is out of this world.

"He has a ton of experience, and that's such an integral hire to the offensive side of the ball. You have to have that guy, and being able to get him really made me feel good."

On the same page:

As long as Vic Fangio's basic philosophies meshed with Matt Nagy, the decision to bring back Fangio as defensive coordinator was easy.

"What he's done with this defense, it's powerful," Nagy said of a unit that improved from No. 30 to No. 10 in total defense in three years under Fangio. "You talk to coordinators around the league, and they struggle against coach Fangio. That's a credit to him and what he's done.

"As an offensive guy such as myself, you respect that immediately. When you can have that guy on your team, you better not lose him. But I don't want to lose sight on the fact that we've got to work together. I wanted him to know my trust for him, and in return, needed trust from him."

Chicago Bears head coach Matt Nagy says he has a lot of trust in defensive coordinator Vic Fangio. Gilbert R. Boucher II | Staff Photographer

Nagy will be the Bears' offensive play-caller while Fangio handles that chore on the defensive side. As for the basic defensive philosophy?

"Don't let teams score points," Nagy said, smiling. "Keep them from scoring."

The Bears were No. 9 in points allowed in 2017.

Learning experience:

Offensive coordinator Mark Helfrich has his theories about developing young quarterbacks like Mitch Trubisky, and how that development works within the installment of a new offense.

"You have to get in their corner at the beginning," Helfrich said. "Challenge them like heck until that first snap and get them thinking about as little as possible at the snap."

Helfrich believes that practicing against Vic Fangio's defense will be difficult for Trubisky early on but also beneficial in the long run.

"He's going to be confused," Helfrich said. "Our job is to dwindle that down to think about one thing. We talk about a flight simulator. We put the quarterback through lighting and thunder and bad weather and winds and darkness. Not every day is blue sky. But we want him on the snap to be thinking, I need to look at A and then B and then C."

While the Bears defense remains the same, it will be a process for the offense to determine what works with the new playbook.

"Any time you have transition, you don't know until you know," Helfrich said. "We're going to go through this and put the plan together offensively. Then we're going to go out and make a bunch of mistakes and go, 'Yeah, let's do this more; let's do this less.' And move forward."

Character builder:

New special-teams coordinator Chris Tabor is barely removed from the nightmare of the NFL's second 0-16 season by the 2017 Cleveland Browns. With that ignominy came a few lessons on perseverance.

"It was haaaard," Tabor said, drawing out the last word. "I'm not going to lie about that. But, at the same time, you just keep chopping wood and try to fix the problems that come up.

"You learn a lot about yourself, you learn a lot about the players, the adversity and how you handle those things. I think in the end it will make you a better coach, make you a better player. It's something I don't ever want to live through again. And we'll probably just leave it at that."

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