That's when he was able to sit behind players like Von Miller and DeMarcus Ware, learning the ropes as an aspiring pass rusher.
The Broncos won the Super Bowl in his second season, but Barrett struggled to find a starting role in Denver.
In his first four seasons, Barrett totaled 14 sacks and forced seven fumbles.
Fast forward to 2019 and he leads the league with 16.5 sacks and six forced fumbles.
The sacks total ties Warren Sapp for the Buccaneers all-time single season record.
"He's doing a great job. They line him up in different spots. He's a very difficult guy to handle," Texans head coach Bill O'Brien said earlier this week. "He's got really good athletic ability. His skillset is similar to Von Miller’s. I mean, he can bend, he can rush, he can get around the corner really fast. Very explosive, very, very good athlete, uses his hands really well. He's an excellent player. He has 16 sacks this year, I think it is, 16-and-a-half I think. So, yeah, he's a problem."
Roby, who's looking forward to swapping jerseys with Barrett after Saturday's game between the Texans and Bucs, said Barrett's a good guy and a family man.
Barrett was married at 19 and fathered three children by 22.
"Great family man, and a good guy," Roby said. "He was always good at getting after the quarterback. He started from scout team, practice squad guy. He did kind of what I did. He was behind two Hall of Fame players, Von Miller and DeMarcus Ware, and he just learned. He took his time, learned by watching all the little things they were doing, working after practice with them and everything. He was kind of quiet, kept his head down and kept working.
"I'm so proud of him for the glow-up, you know what I'm saying? The thing is, I knew. Everyone knew that once he got his shot to be that guy, he would make the plays he's doing. So just the fact he's doing it now makes me happy to see that he's prospering."
Roby said it might be easier to overlook Barrett because at 6 feet, 2 inches and 250 pounds, he doesn't have super imposing size as a linebacker.
Barrett's speed is not overly impressive. He isn't necessarily the strongest guy. Nothing really stands out about him physically.