PHILADELPHIA (973espn.com) - The "engine" of Jim Schwartz's defense hasn't exactly been rebuilt but it did go into the shop for a tune-up during the offseason.

The decisions to move on from two veteran contributors: Michael Bennett, who was shipped off to New England, and the classy Chris Long, who decided retirement was his best option after Philadelphia informed him his desired role as a nickel rusher was not going to be there any longer, is a calculated gamble by Howie Roseman.

The key additions were an interior pass-rush presence to mix in next to Fletcher Cox in former Denver and Jacksonville star Malik Jackson, and the return of Vinny Curry at a much lower stipend after a year exiled in Tampa Bay. Meanwhile, the return from injury by Derek Barnett (shoulder) and Tim Jernigan (back) is also a big piece of the puzzle.

Curry was the starting right end during the Super Bowl LII run with then-rookie Barnett mixing in during the NASCAR package. Now the plan is flipped with Barnett, who is coming off surgery that derailed his sophomore season after just six games, expected to start and get the majority of snips while Curry offers support on both sides behind Barnett and left end Brandon Graham.

As for Jackson, typically Schwartz had shifted an end inside during pass-rushing situations the past two seasons -- either Graham or Bennett -- with Long rotating in at left end. With Jackson's strength as a player being his interior-pass rushing skills the plan is to keep Graham and Barnett home on the outside and let both Fletcher Cox and Jackson be full-time players inside with Jernigan the third man in the rotation.

Cox remains one of the best players in all of football -- arguably the best DT not named Aaron Donald -- but is coming off foot surgery stemming from the divisional round of the playoffs that wiped out his spring.

Graham, the other star up front, signed a three-year extension that will likely ensure that he ends his career where it started.

ELDER STATESMAN

The early years for Graham in Philadelphia were anything but easy. The constant reminders that he wasn't Earl Thomas or Jason Pierre-Paul, an ACL tear which stunted his development, the ping-ponging back and forth from 4-3 defensive end to 3-4 outside linebacker, the thought he would be cut by Chip Kelly to make room for Travis Long all the way up to the 180 where Graham finally lived up to the promise.

From there it became second-team All-Pro honors and the knowledge that Graham was architect of the biggest play in franchise history, the late-game strip sack of Tom Brady in Super Bowl LII which essentially sealed the Eagles' first Lombardi Trophy, all accomplished while fighting through an ankle injury which resulted in offseason surgery before the 2018 campaign and a tweaked hamstring caused by favoring the ankle.

At 31 and with big money on the horizon for Graham, Roseman made sure his offseason plan included keeping the veteran edge player with a new three-year $40 million contract, a deal that could mean Graham finishes his career in Philadelphia wire to wire, something Thomas couldn't do in Seattle and Pierre-Paul was unable to accomplish with the New York Giants.

"He is the heart and soul of this football team," head coach Doug Pederson assessed this spring when discussing Graham.

Part of that stems from the energy Graham brings to work every day, a needed boost through the grind of any NFL season.

“With his energy every single day and what he brings to the defense, what he brings from a leadership standpoint to our team, it's pretty impressive that he's played this long," the coach explained. "Really, to me, he can go several more years. I really do believe that.”

Graham is now under contract through the 2021 season and will be entering his 10th season when training camp kicks off later this month.

Through all the accomplishments, however, Graham still finds ways to motivate himself and one goal he has set for himself is double-digit sacks, something he's never reached with 9 1/2 during the 2017 Super Bowl season as the high-water mark. It's the one stat that the under-educated judge edge players on and the reason Graham continues to be chided by some critics who haven't recognized how complete his game has become for Philadelphia in recent seasons.

“Tenth year, and I’m trying to crack the double digits on the sacks; that’s always been a goal, but I feel really good about achieving that with the culture we have,” Graham said.

That culture is created by Schwartz who leans on the defensive line with Graham and Cox, as the highest-firing pistons in the engine.

“We have Malik (Jackson) in the middle, Fletch (Cox) in the middle. It’s going to be a problem (for opposing teams),” Graham surmised. “... I think we have a chance to do something special. But we also know that we’ve got a lot of work to do."

NEW RUNNING MATE FOR FLETCH

A salary-cap casualty in Jacksonville, Jackson, 29, agreed to a three-year deal worth $30 million. He made the Pro Bowl in 2017 when he recorded eight sacks and four forced fumbles with the Jaguars. Those numbers fell off last season (3 1/2 sacks and No FFs) but he continued to provide consistent heat with 51 quarterback pressures.

Jackson was scheduled to count $15M against the 2019 cap for the Jags and ironically was released to help create space for Jacksonville to make a run at former Eagles backup quarterback Nick Foles in free agency. Originally a fifth-round pick by Denver in 2012 Jackson was a part of the Broncos' Super Bowl 50-winning team before signing a big-money deal with the Jaguars.

He's been able to offer a consistent interior push on the pass rush which is what Schwartz wants but Jackson's run support has been shaky at times.

SOMETHING TO PROVE

The Eagles re-signed Jernigan to a one-year deal hours before the 2019 draft was set to begin. A former starter during the 2017 Super Bowl season, Jernigan is coming off an injury-plagued campaign in which his very career was threatened after a herniated disc injury required surgery.

There is little question that Jernigan can play when healthy and a three-man rotation inside with Cox and Jackson certainly looks impressive on paper.

“I’d rather not look back on that situation. It is what it is. It’s over,” Jernigan said of his off-the-field injury and subsequent surgery. “My focus is on what’s going on now. I’m just excited about what we’ve got going on here.”

Jernigan played just 46 snaps last season and 58 more in the two postseason games and has lost about 15 pounds in order to increase his quickness off the ball.

“I’m here to give it everything I’ve got," he said. "That’s what you’re going to see this year. All go. Everything in."

FAMILIAR FACE

More than a few wouldn't mind spending some of their downtime in Central Florida but for Curry, his time in Tampa felt like one "long offseason." A New Jersey native, Curry grew up an Eagles fan and reached the pinnacle in Minneapolis during Super Bowl LII as part of a group that will walk together in history no matter what happens moving forward.

Curry, though, never got the opportunity for a sequel after being released and ultimately landing with the Buccaneers where things never really worked out. An uptick in snaps early resulted in an ankle injury and Curry trying to fight through it. The result was 2 1/2 sacks in 12 games, losing his starting job to Carl Nassib, and finally a ticket back north once Bruce Arians and Todd Bowles took over the Bucs and went in a different direction.

Curry knew what he wanted after experiencing what he didn't and returned to Philadelphia on a one-year deal for $2.25 million. Although he did have Beau Allen with him in Tampa, Curry missed the camaraderie he developed with teammates like Cox and Graham.

"I just feel like I had a long offseason, that's all," Curry said of his short stint with the Buccaneers. "One thing when I was gone, I still talked to everybody every day."

Now 30 Curry left the Eagles as the starting right end and that's what he was in the spring, although much of that has to do with Barnett sitting out as he continues to rehab from shoulder surgery. The rotation from 2017 will be similar but turned upside down with Barnett, the rookie first-round pick back then who spelled Curry in the nickel package, penciled in as the starter and Curry fitted as the rotational end behind both Barnett and Graham on the other side.

Schwartz's system is something Curry embraces and admitted he missed while in Tampa, where Mike Smith and Mark Duffner handled the defensive play calling last season. Sometimes the grass isn't always greener on the other side of that fence even when the weather is really nice and Curry seems to have figured that out in his "long offseason."

“You gotta understand: one thing a lot of teams probably don’t have, we also hang out together away from the facility," Curry explained. “You know, there’s not [an instance) if a player messes up, we don’t say anything. No. We should be cool enough and brothers enough to be like you need to get your [shit] together. That’s the kind of bond we have.

"It's all about trust, trusting one another."

THE WILD CARD VS. THE OVERACHIEVER

The Eagles figure to have one open DE spot and the contenders are straight out of central casting, Josh Sweat, the prototypical NFL edge rusher, and Joe Ostman, the Rudy-like worker and overachiever.

Sweat was once one of the top recruits in the country as a prep player in Chesapeake, Va. until a devastating knee injury changed the trajectory of his football life. On the fast track to being a college superstar and a first-round NFL draft pick, Sweat suffered a dislocated knee during his senior season at Oscar F. Smith High School that threatened his football mortality. In such cases -- similar to what happened to Teddy Bridgewater before the 2016 NFL season -- if the wrong artery is affected or the proper action isn't taken immediately, the leg could be lost, never mind a career.

In the case of Sweat, the silver lining was that the damage done was repairable and the hurdles placed in front of him, while significant, were not walls.

Sweat, 6-foot-5 and 250 pounds, arrived at Florida State and proved to be an effective player as essentially a multi-year rehab began. He was on the field but there were limitations as far as practice went and an addition to his equipment regimen, a knee brace that is now a part of his game-day life.

“I don’t think I had the college career I wanted at all," Sweat admitted. "It doesn’t really matter anymore. I’m here. I feel like I’m in a much better place as far as using my abilities the way they should be used."

The first-round became fourth round in 2018 for Sweat because of the injury, along with pedestrian production with the Seminoles, the latter of which can be explained by the read-and-react position Sweat was asked to play at Tallahassee, essentially a four-technique hybrid asked to respond to what the opposing offensive tackle was doing. In Philadelphia, Sweat is a wide-9 pass rusher who is asked to pin his ears back and get to the quarterback in obvious passing situations, perhaps as the replacement for Long after getting his feet wet as a rookie before being shut down with a mysterious leg injury.

Ostman, meanwhile, caught everyone's eyes last season with his hard work on the scout team last season when he mimicked players like Khalil Mack, Cam Jordan and Aaron Donald in practice.

“It helped me a lot studying those guys throughout the season,” Ostman explained. “I was able to see how the best in the game succeed every Sunday, so just kind of helped getting an understanding of what they do and why they do their counter moves and their main moves."

An undersized, productive pass rusher in college at Central Michigan, Ostman is generously listed as 6-foot-3. The same could be true of the 260 pounds he's carrying, according to the media guide, but that part of the equation is now true after Ostman put on about pounds in the offseason, something Roseman noted.

"When you look at the transition he’s made with his body just in the offseason. I know a lot of the coaching staff is excited to see him in his second year,” Roseman said.

Ostman said the goal of the added weight while keeping as much of his quickness and speed as possible was mutual.

“They (the Eagles) raised my goal weight to seven to 10 pounds after last season,” Ostman explained. “I kind of knew that, too, looking around at the guys. They were a little bit bigger than me, so I knew that was something I had to get done in this offseason. That was the main goal, to get bigger, but also without losing any flexibility and speed in the process. I’m still working on it, but I’m happy right now sitting around 260 and I feel good out there.”

From a technique standpoint, the next step is developing that counter move all young pass rushers need.

"You can't just run around people at this level," he joked.

With Graham, Barnett and Curry fixtures at DE, the door is open for one and perhaps two bodies but Ostman is still behind consecutive fourth-round picks Sweat and Shareef Miller. Even Daeshon Hall, the rangy player who was once a third-round pick in Carolina, could figure in but Ostman is ready to compete and feels more comfortable as a now second-year player.

“This is my second year now and I do feel a lot more comfortable," Ostman said. "I know with that comes a little higher expectation. I have to go out there and make plays. But really all I’m focusing on is working as hard as I can and trying to be as prepared as I can. You go out there to play hard and let the rest fall into place.”

DEPTH CHART:

LDE Brandon Graham - A relentless two-way player who remains one of the most well-rounded edge players in the NFL.

DT Fletcher Cox - The best interior player in the NFL not named Aaron Donald.

DT Malik Jackson - The knock in Jacksonville was run support.

RDE Derek Barnett - A big Year 3 for the former first-round pick. Trading Bennett was at least partially done to clear reps for Barnett

DE3 Vinny Curry - Should be fine as a versatile situational player but will not offer the same kind of pass-rushing presence as Long.

DT3 Tim Jernigan - Jernigan has a lot to prove after a herniated disc essentially wiped out his 2018 season and any long-term security.

DE5 Shareef Miller - Rookie fourth-round pick figures to be the fifth defensive end and will get a year to ramp up.

ON THE BUBBLE:

DE4 Josh Sweat - Sweat has the inside track for the last DE spot available but injury history is always a concern.

DE6 Joe Ostman - Hard-worker who is a favorite of the front office and the coaching staff.

DE7 Daeshon Hall - Lengthy former third-round pick played opposite Myles Garrett in college. Certainly looks the part but faces a tough numbers game.

DT4 Hassan Ridgeway - A 305-pound trade pickup from Indy who the Eagles believe has some run-stiffing traits.

DT5 Treyvon Hester - Hester is a fingertip away from the 53-man roster and the waiver wire.

PRACTICE SQUAD CEILING:

DT6 Bruce Hector - The numbers are really against Hector, who spent time on the active roster, this season.

DT7 Kevin Wilkins - Rutgers product who looks like he same from versatility from under tackle to nose.

DT8 Anthony Rush - Huge body on the interior who needs a year on the PS before he can think about making a 53-man run.

POSITION GRADE: 7.0 [Moving on from two productive veteran players is a calculated gamble. If Barnett steps up and the new DTs, along with a healthy Jernigan, produce everything will be fine.]

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-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen