You pull out the roster printed on looseleaf and scan the starters and key reserves on defense, and it's practically all there - all-stars, solid veterans, up-and-comers, promising rookies, size, speed, and, yes, a few potential holes.

Any coach in the NFL would salivate over having such a collection of talent on the defensive side of the ball. Five of the starting 11 have been to Pro Bowls. Four rookies are expected to contribute right away.

You watch the games - two in the preseason so far - and you see some splendid individual performances. Cornerback Dominique Rodgers-Cromartie has many saying, "Asante who?" Phillip Hunt has wreaked havoc on quarterbacks, and he's still relatively low on the depth chart.

Rookie Mychal Kendricks has looked like the playmaking linebacker the Eagles have lacked for years. Defensive end Trent Cole heads a line that is 11 deep, should that many make the final 53.

And yet, the whole is less than the sum of its parts. It was that way for most of last season. It's been that way through two preseason games this year. The same problems that plagued Juan Castillo's unit in his first season as defensive coordinator have not gone away.

If it wasn't a trend, the issues could be dismissed during this preseason.

The Eagles did not game-plan for Ben Roethlisberger and his offense in the opener. But Castillo spent a considerable part of last week preparing for Monday night's game against Tom Brady and company.

Patriots coach Bill Belichick rested many of his starters, including the all-pro quarterback, but a letdown was no excuse for not dominating against New England's second unit.

"Yeah, you should dominate," safety Nate Allen said. "But you've got to also realize [the second unit is] no less talented than the first team. They're professionals, too. We just got to go out and keep improving."

Last year, the Eagles defense could not get off the field on third down, especially during the first 12 games of the season. Opposing offense converted on 57 of 150 third downs (38 percent) during that span. Even with the improvement over the final four games - 18 of 61 (29.5) - the Eagles finished 19th in the NFL.

On Monday night, when the Eagles first team played the entire first half, the Patriots were successful on seven of 11 third downs in the first 30 minutes. Ten days earlier in the preseason opener, the Steelers converted on 4 of 8 third downs against the Birds' first- and second-team defenses.

Penalties were an issue yet again. The Eagles committed 123 penalties last season, the most-ever under coach Andy Reid. Twenty-three of them came from three defensive players alone - defensive end Jason Babin, cornerback Nnamdi Asomugha and Cole.

The defense committed five in the first half of the Patriots game. Three were personal fouls. The first team has four personal fouls in just three quarters of play this preseason.

There was one notable improvement at New England: the tackling was crisper. Some of that had to do with Jaiquawn Jarrett not playing with the starters. But Kendricks and linebacker DeMeco Ryans were sure-handed against the Patriots.

The elephant in the room, of course, is whether Castillo has improved as a coordinator. Reid based the improvements he saw in the final four games of 2011 as enough reason to give Castillo another shot, although his flirtation with Steve Spagnuolo suggested that he was ready to move his former offensive-line coach.

Reid, instead, brought in Todd Bowles to head the defensive backs and aid Castillo. The Eagles requested permission to speak with Bowles in January 2011 for their defensive coordinator opening. Miami denied them. Castillo was promoted shortly thereafter.

Make of that now what you will.

Castillo's play calling remains suspect. The Patriots, like many offenses last season, hurt the Eagles with a variety of short passes, screens and draw plays, taking advantage of the over-aggressiveness of the defense. Castillo couldn't seem to adjust.

"I feel like a lot of teams are going to give us that same look," defensive end Brandon Graham said. "They will try the screens and draws to try and slow us down."

Last season, Castillo didn't order up many blitzes, mostly because Jim Washburn's front four was generating enough pressure. He called several pass blitzes against the Patriots, and two times his defense was beaten badly, both times on third down.

In the first quarter, Kendricks and Ryans were sent after Ryan Mallett. But the quarterback dumped a screen to receiver Julian Edelman, who picked up 16 yards on third and 8. A quarter later, the duo blitzed again - this time on third and 9 - and Mallett dumped a short pass to running back Shane Vereen, who scooted 20 yards.

Mallett, by the way, still hasn't thrown an NFL pass in a regular-season game.

Contact Jeff McLane at 215-854-4745, or Follow @Jeff_McLane on Twitter.