To "shock the world," as new Philadelphia Eagles defensive tackle Isaac Sopoaga promised right after signing a free-agent contract last month, the Eagles will first have to have a defense that fits together.

As they head to the start of this year's NFL Draft on Thursday, that remains their biggest question mark.

Can the defensive ends left behind in former coach Andy Reid's 4-3 system fit the 3-4 or multiple fronts new coach Chip Kelly plans to employ?

Which spot is best for second-year linebacker Mychal Kendricks?

Did they do enough in free agency to address the personnel shortages up front and in the secondary?

A series of closed practices during a minicamp last week gave the coaches and the powers that be in the front office some clues. But no player, coach or executive has been interested in sharing anything except how much they love Kelly's fresh methods.

Yet no matter how things went down, it's reasonable to conclude the Eagles are far from done rebuilding a defense that even now barely resembles the 2012 product, which included departed defensive tackles Mike Patterson, Cullen Jenkins and Derek Landri, end Darryl Tapp, linebacker Akeem Jordan and cornerbacks Nnamdi Asomugha and Dominique Rodgers-Cromartie.

Here's a look at the defensive position groups heading into the draft, when the Eagles could well be players in the trade market as well:

• Defensive line: The only reasonable certainties inside are that Sopoaga and Antonio Dixon have the size to play the nose in a 3-4 and will compete with a draft pick or two for a starting spot there.

Defensive end remains the most intriguing mystery on this team. Fletcher Cox, a rookie defensive tackle last year, will be counted on to play outside now, at least on running downs.

After that, it's anyone's guess. Trent Cole, Phillip Hunt and Brandon Graham will almost certainly be switched to outside linebacker, a position they all have to prove they can play.

Cole is going down to 260 pounds from his normal playing weight of 270, he says, because "I'm just trying to get my legs up under me. I'm doing a lot of different things now. I'm dropping into coverage, I'm rushing the passer. ... We don't know where we're going to be at right now."