When the Eagles used the 37th pick in April's draft to grab South Florida safety Nate Allen, it was clear they thought highly of his future in the NFL.

They probably didn't expect it to arrive so fast.

Allen, a 22-year-old from South Florida, was running with the Eagles' first team defense Wednesday, a day after veteran Marlin Jackson was lost likely for the season because of injury.

Allen's fellow defenders praised his physical skills but stressed the importance of honing his mental game - learning the defense, handling pressure, and being prepared to cope with the ups and downs of a long season.

"Obviously in this defense he's got his work cut out for him," strong safety Quintin Mikell said after practice. "You saw the struggles we had last year. But at the same time, he's got the right attitude. He's coming in focused. He's a smart guy. He's fast. He can make plays on the ball. He's got good size."

Later, Mikell added, "You've got to be mental. You've got to be a smart guy, and you have to be able to make checks."

Allen's step into the spotlight of a potential starting job will only add to the story lines around him. Already he bore the pressure of being the player chosen with the so-called "McNabb pick" - the draft slot acquired in exchange for the Eagles' franchise quarterback - and he is trying to step into a position that was, until recently, manned by Brian Dawkins.

"Everybody saying the whole Dawk-jinx thing, everyone looking at him being a rookie, being the Donovan McNabb pick, all that stuff, he's got to deal with," Mikell said. "But if he goes out there and does what he does, don't ask too much of himself, don't put too much pressure on himself, just go out there and play ball, he'll be fine."

If Allen locks up the starting job, it will be the second consecutive year that the Eagles open with a rookie at free safety. Last year, the team started with Macho Harris, a college cornerback, at the position, though he eventually gave way to Sean Jones. Neither nailed down the job. Harris is back at cornerback, and Jones was allowed to leave in free agency.

Mikell said Allen would have some advantages: he played safety through college, and he's getting first-team repetitions early in the off-season.

"The good thing is he's listening. He's taking everything we're giving him, and he's trying to apply it on the field," Mikell said.

Allen said he wasn't taking a starting spot for granted.

"I know I've got to compete, and I've got a long ways to go for anything," he said.

Despite starring in college, recording 85 tackles and four interceptions as a senior, Allen is now facing bigger, faster receivers and smarter quarterbacks, and trying to master a more complex defensive scheme.

He called the defensive playbook 10 times thicker than the one he had in college, then revised it to 100 times bigger.

Quintin Demps, another free safety who will factor into the mix, said a college defense might have one check at the line. With the Eagles, he said, there might be eight.

Draft analysts praised Allen's coverage skills when he came out of college, and he had made at least two interceptions in rookie camp the last two weeks.

"I'm just still learning and trying to pick everything up," Allen said. "I knew I couldn't hold the [starters] back. I had to keep the tempo going."

As much as Allen tries to learn, Mikell said the biggest tests would come when the rookie has to bounce back from errors.

"He's going to have some struggles, but he's got to stay confident in himself," Mikell said. "Obviously we haven't seen that part of him, but he's doing well so far. But you've got to see what you are when you make bad plays."

Allen has three months to get ready.