FINALLY, Sean McDermott had his whole defense together yesterday, the first day of a 2-week, full-squad OTA. The largest Eagles rookie class in more than 20 years was out there in the Nova-Care bubble, 2 weeks of rookie camp under its belt, cutting down a little on the chaos. And all the veterans were in attendance; for the first time in years, no one decided to opt out of an optional activity.

So McDermott could relax, take a deep breath, and start fine-tuning the unit he hopes to field when the season opens in a little more than 3 months. He could . . . ahh, wait a minute. Jeremy Maclin just caught a Kevin Kolb pass over the middle, pursued by new starting free safety Marlin Jackson. Jackson isn't getting up. Looks upset. Now he's thrown off his gloves. Now he's lying on his back while head athletic trainer Rick Burkholder manipulates his right leg. Now Burkholder is helping Jackson off the field. Now Jackson, the ex-Colts corner who tore the ACL in his left leg last season, and the right ACL in 2008, is limping out the back of the bubble, yelling something, very upset. Now he is riding the cart to the main NovaCare building, with his head in his hands.

Later, word arrives on why Jackson was so upset: torn right Achilles' tendon. Very likely a season-ending injury, if not career-threatening, for a guy who has only played 11 games the past two seasons.

So much for McDermott's fine-tuning.

OK, so who is next in line at free safety, the black hole in the middle of the Eagles' defense last season, after the loss of Brian Dawkins to free agency? Second-round rookie Nate Allen? Eager-for-redemption Quintin Demps? Does Macho Harris move back from corner?

"We've got quite a few players back there that we have a lot of confidence in, with Nate and Quintin Demps - Quintin's played before," said McDermott, the Birds' defensive coordinator. "That's why we have a personnel department."

Speaking of which, Eagles general manager Howie Roseman said the team will not be pursuing Rams safety Oshiomogho Atogwe, who became an unrestricted free agent yesterday. "We like what we have, we like our young players," Roseman said.

It seems the focus right now will be Allen and Demps, though McDermott agreed it would be pretty easy to end the rookie-camp experiment with Harris at corner and play him at free safety, where Harris started eight games, with varying degrees of effectiveness, as a fifth-round rookie last season.

"He's an option for sure - Macho's played and started eight games last year. We have confidence in him at more than one position," McDermott said.

Harris was clearly shaken after watching Jackson go down, without being hit.

"It was a moment of silence" after the play, Harris said. "A situation like that, all you can do is just pray, ask God to step in his life for understanding and guidance, but man, I definitely feel his pain."

Harris was asked about making another move.

"Wherever the coaches may need me to help the team," he said.

Allen said he believes he is learning the defense quickly and certainly hopes to contribute as a rookie, though not at Jackson's expense. Speaking before Jackson's prognosis was known, Allen said he hoped Jackson would be back in a few weeks, which obviously is not going to be the case.

If Allen had to step in and start as a rookie, does he feel he could?

"I'm confident I could do that. It's just a matter of learning," he said. "A lot of it is mental, you know? . . . I'm real confident in what I'm doing, but still, I've still got a while to go, got to learn the defense still."

Demps is the guy who was tabbed to succeed Dawkins a year ago, on the strength of a very few snaps he'd played at the position as a brash, confident rookie. Being promoted to such an exalted spot so soon seemed to give Demps a very high opinion of himself, which McDermott did not share. By the time preseason games started, McDermott was looking in other directions. Then hamstring and ankle injuries kept Demps out of five games; he wound up pretty much wasting a year.

Demps came back this offseason with a different attitude. It seemed, after the Birds signed Jackson and drafted Allen, that it might be too late for Demps to regain last year's opportunity. Now, maybe not.

"I'm not sure," Demps said, when asked if he thought he would get more of a look now. "I know my focus is to come out here every day and just get better. I hate to see that happen like that. I've got to really encourage Marlin and pray for him and be there for him."

When Jackson signed with the Eagles in March, he was asked to respond to fans' skepticism about a player who'd suffered back-to-back serious knee injuries.

"I'm confident [reinjury] is not going to happen because I know me. The fans here don't know me, don't know my work ethic, how I approach this game and how positive I am," he said. "I wake up every day and I attack my rehab and I work so that I'll be fine and I'll be out there again. How many times have you heard about a person who's had a clean ACL [tear and repair] then re-tore it? There's not many times that you can find that situation. I've had two great surgeries. Dr. [James] Andrews did a great job fixing both of my ACLs. I've had outstanding rehabs in both of my legs, and this one right here is ahead of schedule, a lot better than my last one was. I bounced back well from that one."

Of course, Jackson was right in a way - he did not reinjure either knee.

His 2-year contract was said to be worth as much as $6 million if he played well, but given Jackson's injury history, it was heavy on incentives, with little money guaranteed.

Herremans hobbled?

Todd Herremans sat out yesterday with a sore left foot, the Eagles said. No more information was offered, but Herremans apparently worked out on his own at Nova-Care.

That would be the foot he had operated on before last season, which caused Herremans to miss the first five games. Svelte Max Jean-Gilles took over at left guard yesterday, with Nick Cole at center, in place of Jamaal Jackson, who is recovering from ACL surgery. Jackson and defensive end Victor Abiamiri (microfracture knee surgery) were the only players not expected to participate.

Birdseed

The sight of middle linebacker Stewart Bradley smoothly covering tight end Brent Celek, forcing a too-high Kevin Kolb throw, would have warmed the hearts of Eagles fans had there been any inside the practice bubble. Covering tight ends has been a huge problem for the Birds. Bradley, who missed last season with a torn ACL, seems to be able to cover his own TE, at least . . . Running back Mike Bell, a free-agent signee sidelined much of rookie camp after tweaking a hamstring, looked fine yesterday. *

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