With Eagles training camp here, talk is heating up about position battles, how many wins the team will have, what will Doug Pederson be like as a head coach and more.

While the Eagles have missed the playoffs for the past two seasons, they decided to stick with the core group of guys from those past two seasons - so here are the five returning Eagles with the most to prove in training camp.

5. Fletcher Cox, DT

The explosive Cox is just 25 years old, and coming off a career best 9.5 sacks last season.  So why is he on this list when it seems the arrow is pointing up?  His six-year, $103 million extension through 2022 with $63 million guaranteed is the reason.

While few think he will fail in the Eagles new 4-3 system led by Jim Schwartz, but he certainly has to prove he is worthy of being on of the top paid non-quarterbacks in the NFL. Schwartz indicated that he will move cox up and down the line, creating match-up problems for opposing offensive lineman.

Quotable: "He fits our scheme. I think we'll have some things for him that will fit him well. He's a tough matchup. He's a tough matchup versus guards. He's a tough match up versus some tackles. And I like some of the stuff that they did with him here last year, moved him around a little bit. They’re all going to know what number he wears -- so it’s our job to create some matchups for him. He's very skilled there. He's a good run player; he’s got great hands. I've said this before, he was drafted for a scheme similar to this, so it will be good to get him back to that and really see what he can do. We expect great things from him.” – Jim Schwartz, Eagles defensive coordinator.

4. Lane Johnson, RT

Johnson has shown flashes during his first three seasons, but hasn’t fully lived up to his first-round selection (4th overall.) The Eagles’ offensive line was a weak spot the past two seasons, and Johnson needs to prove he can anchor the line with Jason Peters getting to the end of the line. Johnson will most likely anchor thew right tackle spot, but will probably move to the left side someday. But a dominating season would make Eagles fans feel better about that move.

3. Ryan Mathews, RB

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Mathews had an up-and-down first season in Philadelphia. He led the Eagles in yards-per-carry and finished second in rushing yards, but again had injury issues that plagued him in San Diego. After missing three games with a groin injury, Mathews must prove he can be the lead back that the Eagles are looking for, otherwise it will be a mix of Mathews, Darren Sproles and rookie Wendell Smallwood. However, the most talent guy of the group is Mathews and in Doug Pederson's offense he could be a focal point just like guys like Jamal Charles, Charcandrick West were in Kansas City and LeSean McCoy and Brian Westbrook were in Andy Reid's offense in Philly.  

Quotable: "Ryan, he can handle all the stuff and the pounding," said coach Doug Pederson. "But with the guys we have - Darren is obviously a big part of that and now with Wendell coming on, I think it could be a little bit of a running back by committee." - Doug Pederson, Head coach.

2. Jordan Hicks, LB

The play-making linebacker was a huge surprise for the Eagles filling in at middle linebacker after being drafted in the third round last season.  However, he has been hit by the injury bug through his pro and college career, missing the final eight games of 2015 with a torn pectoral, but he’s fully healthy entering 2016. This season will go a long way toward determine Hicks future with the Eagles, and that process begins in training camp - can he be the impact player that he was in 2015 as a rookie that remains to be seen.

1. Zach Ertz, TE

No player has more to prove in 2016 than Ertz. Drafted in the second round in 2013, the skilled tight end hasn’t lived up to his potential. He’s shown flashes, recording 35 receptions for 450 yards and a touchdown over the final four games of 2015. But has hauled in just nine touchdowns through 48 career games and has just three 100 receiving yards games. During his three year career, he seems like the guys fans are most excited about at the start of the season, its time for him to prove his new five-year, $42.5 million extension through 2021 was worth it.