PHILADELPHIA - The one, almost unwavering, narrative coming from the Eagles coaching staff during the opening 10 days of camp has been the offseason work of cornerback Nolan Carroll.

"You watched when he first got here (from Miami) to where he is now, he has made some great strides," coach Chip Kelly said. "If you ask any of these players, you talk about our competitions in the weight room and all those other things, the guy who won them all was Nolan.

"We are excited to see where he can take that next step into becoming a full-time starter."

(Listen to ESPN.com NFL Nation Eagles Insider Phil Sheridan)

Almost everything about Kelly's rep-heavy practice system is written in pencil, a concept purposefully designed to allow the maximum number of looks at the maximum number of players.

It is in no way helpful to members of the media trying to cobble together a depth chart in advance of the Eagles preseason opener against Indianapolis on Sunday and Kelly himself made sure Tuesday to note that the team's published depth chart was put together by public relations chief Derek Boyko, not the coaching staff.

There are obvious exceptions to any rule of course and known, All-Pro commodities like Jason Peters and Fletcher Cox aren't rotated in with the second- or third-teams for the sake of extra looks. In fact, none of the entrenched starters are.

Carroll hasn't quite made it to that level yet but he has spent the vast majority of his time as the starter outside opposite Byron Maxwell in the team's base defense. And save for a couple of reps for rookie second-round pick Eric Rowe, it's almost safe to write Carroll's name in pen when it comes to the starting lineup.

So what gives?

This is the game guy who couldn't get on the field last season despite the prodigious struggles of the now-deposed Bradley Fletcher.

As the team's dime cornerback in 2014 Carroll played in less than 40 percent of Philadelphia's defensive snaps, a significant down tick from his last season in South Florida when he started 12 games and was on the field almost 70 percent of the time.

"I was frustrated, angry and a little disappointed (last season)," Carroll admitted. "It wasn't what I thought was going to happen."

Perhaps if the Eagles defensive backfield was successful a season ago it wouldn't have mattered as much to Carroll but the group was universally regarded as one of the NFL's worst, highlighted by the fact that three new starters are set to join safety Malcolm Jenkins this time around

Defensive coordinator Billy Davis took part of the blame for not getting Carroll on the field more last year.

"I've got this beautiful view of hindsight right now," Davis said. "When you're in the middle of it, you don't quite have it, and as it works out and plays out against what you thought, you kind of say to yourself, 'I might have made a mistake there.'"

At first Carroll demurred when talking to 973espn.com about his offseason secret.

"It's a bunch of stuff I did but I don't really want to get into it," the presumptive starter said before letting his guard down.

"My mind set was just different this year. There were certain things I tried to hone in on. Technique wise, I really just wanted to improve my conditioning. Every time I was just sitting around the house, I would just jog a little bit. Jog down to the gas station or whatever. Just jog a mile or two. To do something just to try to work out as much as I could."

"I wanted to make sure all my ducks were in a row when I showed up here in the offseason and the same thing here in camp," Carroll continued. "We have to be able to be in condition to play 85 or 90 plays a game because our offense goes so fast. You always have to be constantly ready to go back on the field and play that number of plays. And to do it week in and week out consistently."

WEDNESDAY CAMP CHATTER:

*Veteran Andrew Gardner was the winner at right guard, handling the first-team reps in between Jason Kelce and Lane Johnson. It was the Georgia Tech product's third practice with the No. 1s, giving him a leg up on John Moffitt, Julian Vandervelde and Matt Tobin, who have each spent two days with the starters.

*After getting a few more looks than Matt Barkley at Tuesday's practice, Tim Tebow took a step back, failing to get the football out of his hand quickly on occasion and struggling with his accuracy in team drills

*A day after rookie first-round pick Nelson Agholor got a look with the No. 1s on the outside, second-year receiver Josh Huff was back in the saddle although Agholor continues to impress and caught a TD pass from Mark Sanchez in red-zone drills on a nice fade pattern. Veteran Miles Austin also got a quick look on the first team in place of Riley Cooper at one point.

* Tight end Zach Ertz was banged up again and left practice, although he remained on the field. The former Stanford star seems to be struggling with a balky right shoulder but the Eagles don't have to confirm injuries at this point.

*ILB Kiko Alonso missed his sixth straight practice due to a concussion and was joined on the sidelines by fellow inside 'backer DeMeco Ryans, who got a veteran's maintenance day. Mychal Kendricks, meanwhile, had a scaled down practice and seemed to be limping a bit as he exited.