Bears general manager Ryan Poles and assistant GM Ian Cunningham spoke to the media Thursday at Halas Hall. Here are four things we learned from their session:

(1) Poles likes the growth he's seen from Justin Fields and was especially impressed with the second-year quarterback's performance in the preseason finale.

Playing the Bears' first five possessions last Saturday night in Cleveland, Fields completed 14 of 16 passes for 156 yards with three touchdowns, no interceptions and a stellar 146.9 passing rating in a 21-20 win over the Browns.

"I think there's progress being made," Poles said. "He looks comfortable. [With] his technique and his fundamentals and his feet—and then a new offense, new coaches, new system—there's a lot going on both physically and mentally. I thought as the preseason has played out and even practice, you could see things start to slow down and him read defenses quicker and pull the trigger, and it was really cool to see him finish up that way."

(2) It would be an understatement to say that Poles has enjoyed working with first-year coach Matt Eberflus.

"I love that dude," Poles said with a smile. "With the schedule and everything, he is detailed, he's organized, he has a team around him to help him be organized. He's consistent. His message is clear. There is no gray area.

"When he approaches the team meetings and gets in front of the guys, he's got juice. But it's not fluff, it's not fake, it's real. And you can feel that energy that he has. The guys love it. I love it. I'm so pumped about his leadership and how he's handled this team."

(3) The Bears are happy for Teven Jenkins and the progress he's made since switching from tackle to right guard in mid-August.

Since arriving last year as a second-round pick, it's been a rollercoaster ride for Jenkins. He missed the first 11 games of his rookie season following back surgery and then sat out seven practices early in training camp this summer with an undisclosed injury.

Jenkins was the subject of trade rumors, lined up as the third-team right tackle upon returning to practice and then moved to right guard Aug. 14. He has since performed well in two preseason starts at his new position.

Asked what's impressed him about Jenkins' journey, Cunningham said: "Resilience. He had an up and down early part of his career … and then for him to come in and then play guard—a position that he wasn't familiar with—it's just a testament to the kid and his resilience and his work ethic. [I] couldn't be more proud of him."

Jenkins slid to guard as part of the Bears' plan to identify their best five offensive linemen.

"We probably look at that as more of a holistic thing than anything," Poles said. "It's like, 'how can we make the best five?' We did a lot of shuffling around. Everyone was aware of that. When we got to this point and he was in at guard, I thought some good things happened on the field during some of the games … so I'm really happy for him and the progress that he's made. He's settling in well and I think he's going to help us there."

Asked if Jenkins should still be worried about getting traded, Poles said: "No. I had a good conversation with him and I told him how proud I was of him. Again, it's about building the best five, and I think we have a good five with at him at guard. So I think it's good for us to have Teven at guard right now."

(4) Poles has been pleasantly surprised with how rapidly rookie left tackle Braxton Jones has developed.

The fifth-round pick from Southern Utah was promoted to the No. 1 offense midway through offseason practices and has yet to relinquish the job.

"We thought he definitely had starter potential and he could develop," Poles said. "[But] I've been blown away by how fast he has developed. There's a lot of credit for our coaches and [offensive line coach] Chris Morgan; they've done an excellent job.

"He continues to kind of check the boxes. You go from OTAs and [you're] like, 'man, the guy looks pretty good.' All right, but we've got to go to training camp, we've got to put pads on. We put pads on and he still does pretty good. All right, let's see when the lights go on and we go to preseason, is he going to do it then? Because the longer you do this, and you've all seen, you see these spikes and then [wonder], 'where did he go?'

"[But] he just continues to climb and get better and better and better. And then now that next phase is Week 1, he's going to see a 'big dog.'"

That big dog is 49ers defensive end Joey Bosa, a two-time Pro Bowler who recorded 15.5 sacks, 21 tackles-for-loss and four forced fumbles last season.

"I told [Jones], too, there's going to be ups and downs, and I think part of being a really good player is the short memory, like, 'how can you overcome some of those bad plays?'" Poles said.

"That's going to be the next step for him, and just seeing those top rushers in this league, it's no joke. A lot of guys struggle with them, but can you battle, can you fight and have that short memory when things go bad, and do you have the toughness to stick in there?

"I'm excited for him, and I'm excited for what he's become. He has not given that spot up and he just keeps fighting and fighting and fighting. I'm proud of that kid."