PHILADELPHIA (CBS) – It took only one play in the Eagles preseason opener to give fans flashbacks to last season. The defense, which had problems doing everything over the last couple of years, most notably tackling, gave up a big play to Patriots running back Stevan Ridley.

Eagles defensive coordinator Billy Davis knows he has a big job on his hands. He knows where he wants to be, and he knows the defense is just not there yet.

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“I’ve been trying to be coy about what we’re running. I’ve been trying to tell everybody we’re heading in the direction of a 3-4 because that’s where we want to be, and that’s what we want to make sure we’re great at, but you still have to factor in the talents of the players that are currently on the roster that you have and what they do best,” Davis told Angelo Cataldi and the 94WIP Morning Show on Wednesday.  “By the time the Washington Redskin game comes, we will be settled in to knowing exactly what the guys can do and we’ll have them do it, and it means more 4-3 aliments, absolutely that’s what we’ll do.”

The Eagles defense has  struggled since long time defensive coordinator Jim Johnson passed away in July of 2009.

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“I’ve studied Jim Johnson’s defenses. The thing that I was most intrigued with coach Johnson’s was he not only pressured, but he gave the illusion of pressure as well as anybody,” Davis said. “So he kept those quarterbacks on their heels with both, “Oh, they’re coming and I’m going to get hit” and, “I think they’re coming and I’m going to make some bad decisions.” I think that was probably the thing that when I’m studying Jim Johnson I’ve taken the most from. The pressure attached to the illusion of pressure is where he was great.”

The Eagles are always a huge focus in Philadelphia. But this year there’s been more national attention, and most of that is because of head coach Chip Kelly. Kelly does things differently, and whether those things work may change the NFL moving forward.

“[Working with Kelly is] outstanding. I have been, 21 years in really the same NFL box. The mindset, the thoughts, the way you do things. To have Chip [Kelly] come in, not only what he’s doing—the best part about Coach Kelly is he has a reason and it is a documented, researched reason for doing what he does. He always talks about answering the why and he does it. Some of the things is like, ‘Oh that makes so much sense! Why didn’t we think of that before!’ It really is,” Davis said. He’s not doing anything because somebody did it before him. He’s doing absolutely everything that he believes in and has worked for him and I believe with all my heart, I know it’s going to work.”

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