LOUISVILLE, Ky. (AP) -The opening question is always the same. Always.

When NFL personnel first meet Amobi Okoye, they don't ask the former Louisville star how he molded himself into one of the top defensive line prospects in this year's draft. They don't wonder about his work habits or pester him about what it was like growing up in Nigeria.

Their question is much simpler, often spoken in hushed tones to let Okoye know it's OK to finally drop his guard and let them in on the secret they think he's keeping.

``They're always like, 'Are you 19? Really?''' Okoye says, shaking his head. ``They say 'You can tell me. I won't tell anybody.'''

Okoye sighs and lets out a little laugh. The questions he's hearing now are the same ones he heard four years ago after joining the Cardinals at age 16, a time when most players are getting ready for their junior year of high school.

``I'm used to it,'' said Okoye, who turns 20 in June. ``People have always been asking me about it. In my head, when I hear it now, I'm like, 'Again?'''

Don't get Okoye wrong. He's not ungrateful for the attention or exasperated by the somewhat skeptical look in a scout's eyes whenever they watch him work out.

It's just he's ready for people to start looking past the date on his birth certificate and concentrate on what's made him a virtual lock to go in the first round: the never-idle motor he spent three seasons harnessing before finally letting loose; the lighting quick way he gets off the ball; the nimble footwork that makes double-teaming him nearly impossible.

``I'm a player, you know?'' he said. ``Let's talk about football.''

Okoye understands the skepticism. Everything about him, from his cerebral, quiet nature to his 6-foot-1, 300-pound frame, suggests he's all grown up. His deep voice rumbles from somewhere out of his thick chest. His words are measured, polite and exact.

``You hear about his age, and you wonder how he's going to fit in,'' said Atlanta defensive line coach Kevin Wolthausen, who coached Okoye at Louisville before following Bobby Petrino to the Falcons. ``But it just goes back to his parents and the way he was raised. He's never known anything different.''

When Okoye moved from Nigeria to Alabama at age 12, he spent two weeks in middle school before voluntarily testing into high school so he could be with his older brother and sister. He joined the football team at Lee High in Huntsville, Ala., after one of his friends told him he'd probably get ``broken'' if he tried to run with the big boys.

``So I was like, 'You know, just for that, I am going to go out there,''' he said.

At that point his impressions of the sport were the blurry images he saw during random games broadcast to Nigeria. The rules were a mystery. He thought the whole thing looked like some chaotic brawl.

But Okoye learned to love football, even if he didn't understand it. He enjoyed being part of a team, and playing helped him fit in with his older classmates, who quickly forgot the kid who'd just knocked them over was three years younger than them.

It didn't take long for colleges to notice. But nearly every one wanted Okoye to redshirt when he got to school to allow his body and his mind to mature.

It wasn't what he wanted to hear. He wanted to play. Now.

``I didn't want to redshirt or grayshirt, nothing like that,'' he said.

Louisville didn't choose Okoye as much as he chose Louisville after attending a couple of summer football camps at the school. He came with the promise he'd be given a chance to get on the field.

``During two-a-days that first year, (playing) is what I wanted to do and I just kept going after it,'' he said.

It worked. Okoye played in 13 games as a 16-year-old freshman in 2003, even picking up a sack. He moved into the starting lineup as a junior, and last season became the driving force on a defense that helped Louisville to the Big East title and a win in the Orange Bowl.

``I think he was simply ready,'' Wolthausen said. ``All we could do with him was screw it up. So we tried not to screw it up.''

Okoye finished with 55 tackles and eight sacks on his way to being a second-team All-American, playing with the kind of intelligence teammate Zach Anderson said ``just proved he's smarter than all of us.''

Okoye etched his place into school lore during a 23-17 win over Cincinnati in October. With the Bearcats driving down the field in the final minute trying for an upset, Okoye's relentless pursuit of quarterback Dustin Grutza became a staple of the team's video sessions the rest of the season. Petrino would point to Okoye's all-out effort as something that should be the rule, not the exception.

It's that kind of attitude that's helped propel Okoye's draft stock. His athleticism impressed Tampa Bay coach Jon Gruden at the Senior Bowl, and during Louisville's recent pro day, he was surrounded by coaches, scouts and general managers eager to see if the 19-year-old was as good as advertised.

Still, the age question lingers. Though he was 16 when he arrived at Louisville, he was still only six or seven years younger than the oldest player on the team. In the NFL he could be sitting next to veterans who were already in high school when he was born.

It's a dynamic Okoye is aware of, but knows there's only one way to earn the respect of his new teammates.

``I'm just going to go in there and work hard,'' he said. ``Those guys have been around a long time. I just want to learn from them and prove that I belong.''