Head Coach Vic Fangio guided Bryce Callahan for four seasons with the Bears as their defensive coordinator. He saw him grow from a practice-squad member early in his 2015 rookie season to one of the league's best slot cornerbacks by his fourth year.
Callahan's improvement was profound, and the best could be yet to come.
"There are a lot of little things that he's mastered," Fangio told Pro Football Weekly last November. "And he can go to the next level as far as reading and dissecting routes and knowing how to play them, maybe playing them a half-second quicker than he did two years ago.
"Those things start to add up."
That "next level" could offer the Broncos increased flexibility with their defensive backs. With Kareem Jackson capable of playing cornerback and safety, Callahan's continued improvement could give the Broncos opportunities to take advantage of Jackson's diverse skill set, while ensuring they're still covered at cornerback.
The versatility of Jackson and the presence of Chris Harris Jr. also provide the Broncos a chance to use Callahan in the pass rush. Last season, he averaged 1.8 pass-rush snaps per game, according to Pro Football Focus. Callahan generated pressure on 13 of those chances, leading all cornerbacks, according to PFF's calculations.
Callahan's pass-rush work fit how Fangio likes to use his defenders in myriad roles.
"It's versatile," Callahan said of Fangio's defense. "It's not like we're always in man or zone. He switches it up a lot, pressure, the whole thing.
Callahan's pressure rate of one every 1.8 opportunities was the best of the 47 cornerbacks with at least six pass-rush snaps last year.
"I think he'll be great," Jackson said Monday.
But Callahan is also a Bronco for what he brings in the huddle and meeting rooms, not just for what he provides on the field. His four years of work with Fangio ensures that Denver will go into the season with at least one key player who understands through experience what Fangio will ask.
"He'll be a guy that some of us will look to lean on with his experience being in that defense," Jackson said. "He's definitely a tough guy. He's great in the slot.
"I just look forward to playing with him. I'm excited about him. I know he has some tremendous physical tools. It's just going to be exciting."