CHICAGO -- At 5-foot-9 and 176 pounds, Purdue junior cornerback Ricardo Allen is a small man in a big-man's game.

The key to his success: not playing like a small man.

Allen, who has started all 25 games of his Boilers career, describes his playing style with one word -- aggressive -- and backs it up on the field. He typically lines up just inches from opposing receivers, even if those men stand more than a few inches taller than him, as they usually do. Whether a receiver is 5-10 or 6-6, Allen's goal is to challenge them from the moment the ball is snapped.

"I used to play down to my size and think because I was small, I'd have to be an off corner," Allen said. "But most big receivers aren't really good on the line. So I have changed."

Allen enters his junior season among the Big Ten's most accomplished cornerbacks. He has led the Boilers in interceptions with three in each of the past two seasons. He has returned three picks for six points, which ties Rod Woodson and Mike Rose for the all-time team record.

Like all cornerbacks, Allen gets burned on occasion. But his production is undeniable: 164 total tackles (118 solo), 6.5 tackles for loss, six interceptions and 14 passes defended.

Not bad for a guy some considered too small to play in a major conference.

"Miami originally offered me, but Mr. [Randy] Shannon didn't like me for my height," said Allen, referring to the former Hurricanes coach. "I had a lot of people who offered me but didn't like my height. South Carolina pushed away from me because of my height. I was recruited by a lot of schools, but when the time came down to it, everybody kind of shied away from me."

The Daytona Beach, Fla., native eventually landed at Purdue, part of a 2010 recruiting class heavy on players from the Sunshine State. Allen rose atop the depth chart immediately and sparkled as a freshman, earning second-team All-Big Ten honors (media) and leading the team in interception return yards (129).

The 2010 season convinced Allen that he could play at a high level.

"It gave me confidence that my size doesn't really matter anymore," he said. "I play with the biggest and I play with the best receivers around."

Purdue lists Allen at 5-9, which he says is accurate. But he adds: "They should list me at like 5-11 or something."

Allen certainly has played bigger than his frame, but he still encounters skeptics, even those across the line of scrimmage and on the opposing sideline.

"I've seen a couple grins every now and then," he said. "They think it’s going to be easy. I've even seen a couple coaches smile at me when I'm going to press. ... Once I make a play, they leave me alone."

Allen expects coaches to continue throwing their biggest receivers at him and challenging him with deep balls or screen passes, trying to exploit the size edge. He has had some rough games against players like Notre Dame's Michael Floyd (12 catches, 137 yards, 1 TD last season) and Iowa's Marvin McNutt (9 catches, 151 yards, 2 TDs last season). But he views them as learning experiences.

"If he's as good as Michael Floyd, it's a long night," Allen said. "If he's just 6-4, or 6-5, it's kind of easy. It's easier to cover the bigger guys because you have more room to touch, more space to work with."

Allen's goal is to be an elite shutdown corner in 2012, which ironically might include recording fewer interceptions, the stat for which he's best known.

He explains that most interceptions come out of zone coverage, which he'll play when it's called. But he enjoys the "personal challenge" of man coverage.

"A man corner doesn't have as many interceptions but has a lot of pass breakups," he said. "If I work hard to get a lot of pass breakups and maybe get a few interceptions here or there, maybe I'll be known as a shutdown corner."

Whether he's in man or zone, Allen will continue to challenge bigger players. He admits he'll trash talk a bit, saying, "If you get in someone's head, you can change the whole game."

"My coach always says I have little-man's syndrome," Allen said. "I always get into personal battles with people who are taller than me."

Purdue hopes Allen never gets cured.