Four years in the NFL is a lifetime.

It is longer than the average span - 3.3 years, according to the Players Association - of an NFL career.

It is a long time to last with one team even though three of the years were spent playing in a scheme not ideally suited to your abilities.

Vinny Curry's first four years in the NFL were noteworthy in that the defensive end has come full circle. Curry went from second-round draft pick to buried on the depth chart to odd man out after a coaching change to almost traded to underused and then back to the scheme in which he started.

And he stopped off at the free-agent cash machine along the way. The Eagles gave Curry a five-year, $46.25 million contract this offseason based partly upon expectation. His first four seasons hinted at his potential if he were to play more.

The first week of training camp has done nothing to counter that belief. Curry has assumed the role of alpha dog defensive end at practice. He's been paid, but, unlike so many players who have earned big-money second contracts, Curry has played only a fraction of how much he is likely to play in Act Two of his career.

"I just want to be one of the cornerstones of this defense, one of the major parts when you walk away this season talking about the Eagles defense," Curry said. "I just want my name to pop up in the conversation."

It's difficult to say how much Curry's name popped up in other teams' free-agent discussions. The Eagles locked him up more than a month before he was set to hit the market. But teams with 4-3 defensive fronts - particularly ones as aggressive as the one Jim Schwartz has brought back to Philadelphia - were likely set to pounce.

Despite playing just 31 percent of the snaps over the previous three seasons, Curry had 161/2 sacks. In 2014, he averaged a sack every 29 pass rushes. Not even the Chiefs' Justin Houston, who led the league in sacks that season, could claim a ratio that productive.

But Curry, who grew up an Eagles fan, wanted to stay. It helped that Schwartz's scheme would allow the 28-year-old end to do what he does best - play downhill.

"There's a reason we re-signed him. We think he's a good player," Schwartz said. "I mean, certainly with good players, you want them on the field more. We think he fits the system."

Curry couldn't make the full transition when Chip Kelly, Bill Davis, and Jerry Azzinaro installed a two-gap 3-4 front base defense three years ago. The linemen in that scheme were primarily asked to take on blockers, read, and then react. Asking Curry to wait to attack would be like asking Donald Trump to refrain from responding to his critics.

So Curry was essentially relegated to third-down duty.

"I can honestly say this, and you can ask them," Curry said of the previous coaching regime. "Whatever they asked of Vinny Curry, I tried hard to do it."

Davis even had him play some outside linebacker during camp a year ago. Curry never publicly complained even when Kelly and Azzinaro gave him lukewarm praise. But it was clear the usually vibrant Curry had gone into his shell.

He's broken out. Curry has been a constant disruptive force during camp. Schwartz has lined him up primarily on the left side so that he can take advantage of the NFC East's weak crop of right tackles.

"I'm not head up on a guy. So me being head up on a tackle last year already eliminates your get-off, which is one of my strengths," Curry said. "I can just now work [the tackle] on edges and make him play my game."

A perfect example of the new and improved Curry occurred Thursday during one-on-one drills. He gave Dennis Kelly one of his patented stutter bull-rush moves. The tackle was caught off balance, and Curry knocked him onto his rear end as he plowed straight ahead.

"He tried to jump me," Curry said. "I didn't mean for that to happen to him."

Curry's combination of speed and strength made him difficult to block as a pass-rush specialist. The additional snaps should increase his statistics and allow him to get into a rhythm. But he could see double the amount of playing time now that he's playing run downs. He said he's prepared for the load.

Curry spent the summer working out with fellow defensive end Connor Barwin and center Jason Kelce in Ocean City, N.J. He had been asking Barwin to stay local and train with him for two years. Former Eagles defensive end Trent Cole was there, too.

"He's in a good place," Barwin said. "He has a contract that gives him some security, and he's in a system that fits what he does."

Curry said he weighed as much as 287 pounds before the 2013 season. But he played at 275 last season and said he plans to stay at that weight. Schwartz said that Curry was "multi-dimensional enough" to "rush inside," which is what he did for most of the last three seasons.

But that was then. And this is now. Curry said he hasn't changed.

"It feels good, but at the end of the day I put a lot of pressure on myself," Curry said. "Sometimes you just have to take a deep breath and let it flow."

jmclane@phillynews.com

@Jeff_McLane