ENGLEWOOD, Colo. --By most measurements, Bradley Roby's rookie season was a success. His progress at coverage and diagnosing developing plays was palpable, and his confidence grew. The Broncos' 2014 first-round pick overcame struggles during OTAs and training camp to become one of their most dependable defenders.

The perceived character concerns that led to his slide down the board in the first round were forgotten. What the Broncos drafted was a diligent, determined, driven young cornerback who channeled his athleticism.

"Last year I was debating on whether to even go to the draft," he said, adding that his advice to players in a similar situation this year was to "stay positive.

"Everything happens for a reason. I can say everything happens for a reason. It proved itself true for me. They have to just learn from their mistakes and learn at this level you have so many eyes on you, so you have to be careful and make great decisions."

What followed for Roby was a best-case scenario in which he found an immediate role that allowed him to develop while three Pro Bowlers in the secondary shouldered the pressure.

In the wake of that campaign, new defensive coordinator Wade Phillips wants to find ways to get Roby on the field -- even though it could take some tactical tweaks, since he sits behind Chris Harris Jr. and Aqib Talib.

Coaches, teammates, observers agree about Roby: his rookie season was exactly what you'd hope it could be. The only person who doesn't see it that way is Roby, based on the grade he gave himself.

"C-minus," he said after veteran minicamp practice Wednesday. "I know C's get degrees [but] I don't think it was that good.

"This year I think I'll be a lot better, a whole lot better. If people think I played well last year, then I can't wait to show them what happens this year."

The quest for improvement explains why he lingered on the field for an extra 30 minutes after practice Tuesday and Wednesday, receiving extra coaching on his technique long after his teammates retreated to the locker room. Just as he did last summer with Hall of Famer Rod Woodson, Roby put in extra time to hone his craft.

"I think a big thing of mine last year was I messed up a lot in technique. That's what I'm working on now," he said. "If I can get that done now, then by the team the season comes it's going to be first reaction and muscle memory. That's really what I'm working on.

"I want to be perfect," Roby added later. "I don't want to just be another player who just comes into the league, plays a few years and then you don't hear from them. I want to be one of the top guys. That's my goal. That's what I'm working to. Until I get to that, you won't hear any A-plusses or As from me."

If he succeeds, he will make himself indispensable. His progress last year was one reason why Head Coach Gary Kubiak floated the notion of using Roby at safety in some packages; he wants to get him on the field.

"We're going to try and get all our best players [out there]," Phillips said. "In certain packages we have three corners all the time, we may do that. Or we may look at him some at the safety position. If a player is good enough, we'll get him on the field. We'll come up with a package if they can play."

The notion of using Roby at safety remains in play, but the Broncos shelved it during this stage of defensive installation.

"We're looking at our safeties as safeties right now," Phillips said. "Roby is playing pretty good at cornerback right now. All that will come later, I think. We just want to get everything in. He's a smart guy. Obviously he can do a lot of things. He looks pretty good at corner."

And while Roby is open to anything the coaches present, cornerback is where he wants to make his name.

"I'm a corner," Roby said. "We talked about the safety thing a little bit, but right now at this time we're just worried about corner. If that comes down the road and it happens, I'll [be] into it. Right now I'm focusing on corner. That's what position I like to play. That's what they drafted me for. Right now, I'm learning the defense at corner."