CHARLOTTE — Confidence has never been a problem for Corey Thornton.

And neither has the willingness to put in extra time, to develop on what was already a good start to his NFL career.

And those who have watched him every day point out that he's been this way from the start, never seeming out of place, or like the moment was too big for him.

Not when he was an undrafted rookie who made an immediate impression at his first minicamp. Not when he subbed for a Pro Bowler in training camp and didn't just hold his own, but stood out. And not when he got his most extensive action in the regular season last week against the Falcons, and made plays.

"It was going to come, of course, one way or another," Thornton said this week. "That's why, even at times when I wasn't playing, and Jaycee (Horn) was back, I'm preparing like I'm going to play.

"And I just stuck with it, you know, until the opp came. And when it came, I just stuck with what I was doing."

That kind of confidence is inherent in the position, whether it's Jaycee Horn or Mike Jacksonor a rookie who wasn't drafted at all. But Thornton also has something beyond a simple swagger, which makes his growth appear sustainable, and something that will continue.

When defensive coordinator Ejiro Evero is asked about Thornton's game last week — which included five tackles, two passes defensed, and a forced fumble — it sounds like he's reading a shopping list for all the qualities you want in a cornerback.

"He did a great job, he was very effective," Evero began. "He knocked out the one fumble, he made the play in a deep part of the field in one of the last third downs of the game, he was active in terms of throwing his hands, being physical on the edge versus blockers, good coverage snaps, and so he did a really, really good job. The one thing about Corey though that, since Day 1, since he's got here, his preparation habits have been, second to none. I mean veteran habits, in the classroom, on the field, in the training room, in the weight room, how he takes care of his body.

"This guy is driven. He's on a mission. He's not going to be denied, and he's really just done a heck of a job. So it's great to see, when a guy has those type of habits and preparation, when those things come to life in the game. So, yeah, he's going to have a lot of opportunities moving forward."

Evero was then asked if there was a moment when he realized Thornton was ready for this, and he said that it's been an ongoing discussion since he arrived.

"Well, it's pretty funny. I was talking to one of our coaches about this the other day, and we've had these moments really like all through the year," Evero said. "And it's just like, you're always nervous with a rookie and getting them out there the first time and all that, how they're going to respond under the bright lights. But since Day 1, he came in here competitive, not afraid to cover anybody. When Jaycee was injured during training camp, he was taking a lot of reps with the first team group, made a lot of plays, and didn't shy away from the moment at all.

"Did a really good job in the preseason games as well, and just even through the season, the way he works in the look teams, this guy was just in everything he does, he's preparing to go play the game. And so he's just in all of these moments he's excelled and his confidence is really shown throughout the whole thing. And that's always the big thing, some guys have to go out there and have success to gain confidence. He didn't have to do that; he had it built in, and it's not an ego or overconfident type of thing. It's just this guy just has true belief in his ability, and I think a lot of that comes from the way he prepares."

And if you want to see that preparation, you have to be prepared to show up early.

He realized early on that to make a name for himself here, he was going to have to work. So he attached himself to the people who work the hardest. That meant showing up for practice to prep with running back Chuba Hubbard, and turning it into a race to see who got to the practice field first. Thornton actually won that race once, but Hubbard's a determined sort.

But Thornton's been there right alongside Hubbard since, logging those hard hours.

The good news is, he has role models and guidance. In addition to passing game coordinator Jonathan Cooley and secondary coach Renaldo Hill, the Panthers also have defensive assistant Kevin Peterson working with Thornton every day. The veteran coaches are helpful, but Peterson brings a different perspective since he's not far removed from his playing days.

The 31-year-old Peterson spent six years in the league as a cornerback with the Bears, Rams, Cardinals, and Titans before injuries cut that short and put him on the coaching track. The time spent with the Rams put him in Evero's orbit, and he joined the coaching staff this year, giving another body to help develop young players like Thornton.

So from the start, Peterson's been alongside Thornton, the two of them growing in their careers together.

"KP, that's my boy," Thornton said enthusiastically, because that's how he says things. "We've been locked in just, just watching tape, just both of us getting better, him trying to help me get better with, with both the corner and the nickel spot, just doing extra, putting in the extra time to make sure that I've got it. So I've just been with him the whole time; he's been helping me get right, good dude.

"It's great, man. He's a player, so we can kind of connect and bond on the same things, like whatever it is that I'm going through, he done went through. So he has experience, so I can ask him questions on certain things, how he sees certain things that he could let me know, so I can learn a lot from KP, man."

Peterson laughed and said he appreciated any credit Thornton gave him, but the rookie corner came in determined to create this kind of role for himself.

Peterson said that in rookie minicamp, that competitiveness was evident whether Thornton was matched up on another undrafted player, or a top-10 pick like Tetairoa McMillan. A player as talented as McMillan is always going to get his. But Thornton got a few as well.

"Literally his first practice when they had the rookie minicamp, I mean, you could just tell," Peterson said. "You never know going into it, but OK, he's here now, so obviously he has the ability. And in the meeting rooms he's always good, talking and speaking and asking questions. But you never really know until somebody gets out there on the practice field and performs.

"And he shined early on, like within his first practice, and it's like, OK. You always see flashes of things, but you want to see if people can be consistent because if that's what this league is about, being able to be consistent. He had a few press reps against, TMac, and we were like, OK, this is one of our high draft picks, and this is the undrafted corner and he held his own, and we were like, OK. TMac's obviously been doing great, so then to see Corey do that early on as well, it's like, OK, maybe we got something there."

Peterson's often out there with Thornton during that long stretch before practice, when it's Hubbard and the rookie and a handful of others. And in those moments, they talk about the fine points of technique, reemphasizing the teaching points from that day's meetings.

"Sharpening those tools before practice," Peterson calls it.

And being willing to spend that time doing the rote work stood out to all the coaches, because Thornton's been that way since he walked in the door.

"I mean, that's just the type of player that you always want," Peterson said. "Somebody who's hungry, who just wants to be out there, who wants to go out there and prove themselves, who wants to be on the field, and who wants it, you know what I mean? Those are always the best type of people to have in the building. I think it's his determination. You never know how rookies are going, how anybody's going to pan out in the NFL because it's a new jump, but just his eagerness, his hunger to want to be out there. Coaches give him all the information, but then he brings it to life. He really wants to prove himself and show that he can have success in this league.

"This is a testament to who he is. That natural competitor, getting out to the field to make sure he's warming up and getting the things that he needs to do to be successful in practice, or if it's watching film so he can play on Sunday, this isn't something that just comes out of thin air. This is something that is his character and who he is."

As he's earning his place, that confidence doesn't wane. He feels like he belongs out there alongside players such as Horn and Jackson, so he can continue to build on this and make himself part of that "brotherhood" on the field.

"It's just been the same even when I wasn't getting plenty of time," Thornton said. "It's always staying ready, even when I wasn't getting plenty of time preparing like I was going to play, so nothing really changed. Just continue to stay ready and do what I'm supposed to do.

"I just want to be the best version of myself. They always say, if you know what you're doing, you can play faster, so I just kind of want to know my job and know it well so I'm able to show what I'm about, just continue to get better each game, just elevate up, learn from my mistakes, and just play hard."

That part doesn't seem to be a problem for Corey Thornton, and he's willing to show up early and stay late to prove it.