What will Castillo's defense look like?

How badly does Juan Castillo want to succeed as the Eagles new defensive coordinator?

He would kill for it.

Maybe not in the literal sense, but I can't say that for certain after sitting down for an hour-long interview with Castillo recently.

"I can't fail my family, brother," Castillo said. "I got four boys. I don't want to fail them. I can't fail them. And that's a big incentive when you think about it. What would you do for your kids? You would kill somebody for your kids. … So that's what at stake."

Andy Reid's decision to take his offensive line coach and name him the defensive coordinator is still, to be honest, a head-scratcher. I think I speak for the majority of fans when I say I remain skeptical.

"If everybody wants to think that, that's alright with me," Castillo said. "Either way, I'm going to have to prove it."

Castillo has spent much of his life proving people wrong. But this is easily his biggest challenge. All eyes will be on the 51-year-old next season – if there's a next season, of course – and that pressure could be burdensome.

Reid didn't give Castillo much wiggle room. If the defense fails early it will only provide fuel for critics. That short leash and the lockout will likely keep Castillo from overhauling the defense. He has said as much.

But fans still want to know: How will Castillo's defense differ from that of his predecessor, Sean McDermott? We've already gotten a few clues. Castillo has said he and his staff have been simplifying the terminology. Reid has said the defensive ends, now under the stewardship of defensive line coach Jim Washburn, will often line up as nine-technique ends.

But what about an overall philosophical shift? Will the Eagles continue to implement a defense predicated on pressuring the quarterback and creating turnovers or will Castillo blitz less and have more of a bend-but-don't-break scheme? With the Eagles' quick-strike offense it would make sense to not be as aggressive on defense.

"Just because you don't blitz doesn't mean you're not being aggressive," Castillo said. "We got four good defensive linemen and on third down coach Washburn will put four guys that can rush the quarterback."

I doubt we'll see much Tampa 2 out of Castillo, but I wouldn't be surprised if the Eagles blitz less frequently. McDermott became, in some ways, a mad scientist with his blitz packages. He was also too insistent that linebackers fill their gaps – the middle linebacker has the A and B gap, etc. – instead of letting them play instinctively.

Castillo, a former USFL linebacker, is inheriting a corp that has undergone a major transformation in the last two years. The Eagles have drafted six linebackers – Moise Fokou, Keenan Clayton, Jamar Chaney, Casey Mattews, Brian Rolle and Greg Lloyd -- in the last three drafts. Ernie Sims, Omar Gaither and Akeem Jordan remain on the roster, but they won't be back.

Stewart Bradley may be the only pre-2008 draft pick that could be back next season, but his free agency status – Will he be unrestricted or restricted in the new CBA? – could signal his end in Philadelphia.

"We have to see," Castillo said. "Stewart is still [here], so we're not sure about that. So we'll just have to see when we start what we have."

Reid has said that the Eagles are still an unfinished product, what with free agency still on hold. So Castillo doesn't really know what he will have for next season. He admitted to constructing starting 11s in his head, "but I do it with the people I have right now," he said.

So who's the right cornerback?

"There would be a little competition on the right side," Castillo said.

[Insert joke here.]

As for Castillo, he won't fail for a lack of trying. He famously works long hours and has been coming into the office at 3:30 a.m. during the off-season. He said he even plans on working a few hours a day during vacation to "get ahead."

"Everybody not like you, and you don't want them to be like you because you can't move up," Castillo said. "Everybody's not like me or coach Reid."

Hard work can go quite the distance, but it can only travel so far. There's something to be said for experience. Castillo has never called plays in the NFL. In fact, he hasn't done it at any level for over 20 years. And then there's the kind of talent that can't be taught or found 3:30 in the morning.

One of Reid's reasons for promoting Castillo is very similar to how he evaluates players. The Eagles sometimes overvalue players because of their work ethic and their enthusiasm for football. There is value there. But it's led to a few reaches in the last two drafts (see: Brandon Graham, Daniel Te'o-Nesheim, Jaiquawn Jarrett and Curtis Marsh).

Those players could end up rewarding the Eagles' faith, as could Castillo.

He may not even need to kill someone.

Castillo was thinking about someone's death, however, when he was expressing the importance of being successful and providing for his sons.

"When you die … when you're laying on that thing, you want to be able to look them in the eye and say, 'Hey, man, I did everything I could for you,'" Castillo said. "I hope when I go I can say that."