WHEN EAGLES fans talk about their concerns going into the season, you hear a lot about the offense.

There's the wide-receiver situation, and rookie DeSean Jackson's potential impact, especially now that Kevin Curtis is sidelined after sports hernia surgery. Hamstrung Reggie Brown wasn't able to practice yesterday, further adding to the wideout scrutiny.

There's Donovan McNabb, and how much a healthy L.J. Smith will help him, and whether right guard Shawn Andrews is ready after missing most of the preseason while battling depression. There is the load Brian Westbrook must carry, and the question of whether Lorenzo Booker can help him shoulder it. There's the age of the offensive tackles, who will be 34 (Tra Thomas) and 35 (Jon Runyan) by the end of the season.

Absorbing as all those offensive issues might be, there also is an awful lot we don't know yet about Jim Johnson's defense, a lot that we ought to start finding out on Sunday, when the Birds take the field for their opener at home against the St. Louis Rams.

The defensive questions haven't been as prominent, mostly because everybody thought the defense was good enough to make the playoffs last season when the Eagles ranked 10th in the NFL in overall defense, ninth in points allowed, and nobody important left.

The Birds were the only NFL team to miss the playoffs and rank in the top 10 in offense (sixth overall) and defense. This was mainly because they ranked 17th in scoring. Hence the questions about the offense (and to some degree, the special teams).

But the defense figures at least a little into that equation as well — the Eagles ranked last in the league in takeaways last season, scoring no defensive points and setting up very few. That was one of the things Johnson wanted to fix in the offseason, along with strengthening the pass rush from sources other than Trent Cole.

In the preseason, there were glimmers of the kind of dominance Johnson is hoping for, the kind Johnson's defenses were known for much earlier in this decade.

"I think I'm anxious [to see]. I think everyone is anxious," John-son said yesterday. "It's a long season. We don't get a chance to play [as a unit] that much in the preseason. All of a sudden you get 60 or 70 snaps and a lot of things can happen. We want to find out what kind of pass rush we have. We want to find out what kind of turnover team we are. I think we're going to be a good cover team. There are certain things we want to find out, and you don't find them out until you play maybe 60 plays in a game."

Cole made his first Pro Bowl last season. He starts off this season matched against Orlando Pace, who played in seven of them in a row, from 1999 to 2005, but was limited by injuries in 2006 and missed last season entirely after suffering a shoulder injury in the opener.

"He's held down some guys," Cole noted. Pace is 6-7, 325, one of the all-time greats at his position. "I'm going to go out there and give it my best."

Cole was asked if this is the best Eagles defense he has played on. "I don't know, but I want it to be, and I think we're going to get there," Cole said.

The focus on turnovers, and on trying to do something with them, is obvious in every practice. All summer, Johnson's defenders have been scooping up and running back every loose ball, even if the play would obviously have been blown dead.

"We've been working on that all offseason long,'' Cole agreed. "We pick that ball up and we run it back, no matter what happens."

Toward that end, of course, the Eagles signed the top free agent on the market, cornerback Asante Samuel, who has picked off 16 passes over the past two seasons. They added him to a cornerback rotation that includes Sheldon Brown and Lito Sheppard; as Johnson noted yesterday: "The thing we have with those three guys is, we have really good matchups. We have three corners there who can cover a lot of people. We can maybe play some more man coverage, more man blitzes."

One of the big objectives of the offseason was to solidify the end position opposite Cole. That hasn't happened yet. Free-agent signee Chris Clemons has recovered from his calf injury and is expected to play against the Rams, but Johnson said Clemons is "at least a couple weeks behind'' in learning the defense. Victor Abiamiri remains sidelined with a wrist injury.

So the starter will be Juqua Parker, who was Juqua Thomas last year, before fulfilling a promise to his late birth father. Behind Thomas, well, that's a good question. Clemons? Darren Howard? Rookie Bryan Smith?

Johnson also is looking for turnovers, and big plays in general, from his revamped linebacking corps. Chris Gocong proved he could play the strongside last season, and Omar Gaither did a solid job in the middle, despite being undersized. Veteran Takeo Spikes was OK at WIL, but didn't do anything special, so now he's gone, Gaither is back at WIL, and the middle belongs to bigger, stronger Stewart Bradley, who seems to have everything except experience.

Overall, it's a young unit, for the second year in a row. With Rocky Boiman not making the team, even the backups are young.

"They've been very consistent [in the preseason]," Johnson said. "We always want them to make more plays, but they've been very consistent, and I expect them to do well Sunday."

Bradley smiled when asked about the defense yesterday, for the eleventy-billionth time.

"It's going to be good," he said.

It sounded like a promise. *