Nolan Carroll's climb to the top of the cornerback depth chart shouldn't come as a surprise to anyone who watched him break up pass after pass last spring.

Despite a strong period that carried into training camp, Carroll fell short of supplanting incumbent starters Bradley Fletcher and Cary Williams last season. In retrospect, giving Fletcher the nod over Carroll may have been the most costly decision of the Eagles' playoff-less 2014.

The starting position opposite prized free agent Byron Maxwell is clearly open this year, and through the first month of spring workouts, Carroll has made it difficult for defensive coordinator Bill Davis to overlook him again.

Chip Kelly singled out Carroll during the first week of organized team activities as one of the players who has excelled this offseason. The Eagles coach hasn't been the only one. From his competitors at cornerback to new defensive backs coach Cory Undlin, Carroll so far has made the most persuasive case for Fletcher's old spot.

"They're all competing right now. We'll find out where we get to when we start playing games," Undlin said last week. "But Nolan has come in with the mind-set that he's going to get [better] - exactly what we want in every player. A growth mind-set.

"He's not satisfied with where he was yesterday. So every time he comes into the building his mind-set is telling him, 'Listen, I'm going to find a away to get better than I was yesterday.' I believe he's done that every single day he's been here."

A cynic could point out that Carroll's effort comes in the final year on his contract, but the 28-year old was consistently one of the players Kelly and Davis praised last season. Despite having never played inside, the adaptable Carroll was taught on the fly how to play a quasi-linebacker spot in the Eagles' dime defense.

But he's back on the outside, where he started 27 games for the Dolphins before signing a two-year deal with the Eagles. Carroll said that he's relishing the opportunity, but that he isn't taking anything for granted. That kind of attitude has helped him move ahead of Brandon Boykin and rookie Eric Rowe, and likely contributed to Walter Thurmond's move to safety.

"It's a great opportunity. I'm just going out there competing, making plays," Carroll said. "I'm trying to do everything I can to help this team. Every day I go out there it's just a mind-set of always trying to get better and always competing."

Undlin has instituted a points system for his defensive backs that monitors their practice habits. Points are given, of course, for interceptions and pass breakups, but minor details like trying to strip the ball or using your hands properly in press coverage are also rewarded.

Carroll has won many of the competitions, Undlin said. The cornerback said that he has bought into the coach's methods.

"We're setting the bar high for us to be successful," Carroll said. "We want to be the best group back there. Last year, everybody's talking about how we were the worst group back there. This year coming in we took offense to that."

Carroll, Boykin and safety Malcolm Jenkins are the only regular holdovers.

When Fletcher didn't play in the season finale - after a difficult stretch of games - Carroll started in his place against the New York Giants. He played through injury and had to be rusty after 15 games inside, and the Eagles allowed their most yards through the air that day.

Carroll was hardly the lone culprit, but he won't likely have to worry about jumping back and forth. With the addition of three-down linebacker Kiko Alonso, Davis may nix his dime package. Even if it returns, Carroll has proven to be too valuable on the outside.

Both receivers and his competitors for the starting spot have said they feel Carroll's presence in the secondary.

"He's working hard. You can't take anything away from him," Boykin said. "He's working hard in the weight room, outside, and even off the field."

@Jeff_McLane