As we count down to the beginning of training camp, the Daily News will answer a Big Eagles Question each day. In Part II, how will the defense — and the wide-nine — fare with its additions, subtractions and mainstays under second-year coordinator Juan Castillo?

SO, CAN THE wide-nine defensive line scheme progress in its third iteration in less than a year?

Yes … assuming Trent Cole remains healthy and productive.

Any defense, even Juan Castillo's, works with Cole as its fulcrum. His presence recalls that of Brian Dawkins: The offense always knows where Trent Cole is, and it adjusts accordingly.

With due respect to Hugh Douglas and William Fuller, no Eagles end has drawn this much attention since Reggie White.

Evidence? Good question.

Cole collected 11 sacks last season and failed to make the Pro Bowl for the second straight year.

Meanwhile, free-agent addition Jason Babin had 18 sacks and went to his second straight Pro Bowl; he also went in 2010, when he played end in Jim Washburn's wide-nine scheme with Tennessee.

But consider this:

Cole missed games against the Bills and Redskins last season. Babin had no sacks in either of those games.

Washburn lined Babin up on his accustomed left side, switched him to Cole's right side, stood him up, stunted and twisted … and, nothing.

Nothing, without Cole attracting double-teams and running backs, without teams rolling away from Cole, and into Babin's hungry arms.

This is not to denigrate Babin. They operate in harmony, a horrifying chorus of violence that helped the Eagles tie for the league lead with 50 sacks, 46 of which came from Washburn's rabid defensive line.

The Eagles should have 60 this season, in part because the line has better support.

Lockdown corners Nnamdi Asomugha and Dominique Rodgers-Cromartie will return to their natural roles as man-to-man press corners. The gambling coverage of Asante Samuel crippled the scheme because quarterbacks last season looked to dump underneath Samuel's soft zone coverage then counted on Samuel missing tackles. Too often, Samuel obliged on both counts; now, he is in Atlanta.

The Eagles added veteran DeMeco Ryans at middle linebacker, a massive upgrade to the carousel of young and small hopefuls from 2011. They drafted Mychal Kendricks in the second round to play beside Ryans, another upgrade.

They are new to the system, which is a hindrance, but the rest of the corps simply failed.

Young safeties Kurt Coleman and Nate Allen played well at the end of last season. Knee surgery ended Allen's rookie season in 2010 and a concussion sidetracked his comeback last season, but the second-round pick played to his pedigree in the last month.

And then there is the middle of the wide-nine.

The Eagles' first-round pick, Fletcher Cox, gives ample cause for optimism. A legitimate monster tackle — 6-4 and nearly 300 pounds — he moves like a man 4 inches shorter and 20 pounds lighter. He can rotate to end, if needed; indeed, his athleticism effectively gives the Eagles three ends on the field, making stunts and twists particularly effective.

But Cox is new. What the Eagles already had should cause even greater optimism. It is the second season in the system for tackles Cullen Jenkins and Mike Patterson, which will help.

It is a make-or-break season for 2010 first-round end Brandon Graham, who will be playing for his professional life.

And it is a contract year for Antonio Dixon, the 6-3, 322-pound undrafted project who fought his way into 31 games in 2009 and 2010, 10 of them starts. He was a major piece in last year's plan before a torn triceps in Game 4 ended his season.

Without Dixon, the Eagles had no chance against the run.

Not in the first iteration of Castillo's defense, with Patriots castoff Jarrad Page starting at safety and smallish fourth-round rookie Casey Matthews starting at middle linebacker.

Not in the second iteration, when Allen reclaimed his spot and Moise Fokou, then Akeem Jordan, manned the middle linebacker position.

In this iteration, the Eagles have more than a chance of stopping the run.