RIVER FALLS, Wis. - Booing Rudy Niswanger may not be smart.

Kansas City's cerebral young center almost never forgets anything he does, sees or hears. And one day he may be standing over your unconscious body holding a sharp knife.

An honors graduate from LSU with a degree in kinesiology, Niswanger was accepted into medical school before he was ignored in the 2006 draft. He seriously thought about becoming an orthopedic surgeon.

After the disappointment of the '06 draft, a medical career seemed the only sensible path for the 6-foot-5, 300-pound native of Monroe, La. The NFL seemed to be telling him the odds against a future in football were long, very long.

Whether he would thrive in the academically stimulating environment of medical science seemed beyond question. Not only had he been a first-team academic All-American, he'd also won the prestigious Draddy Trophy, which the National Football Foundation awards each year to the top scholar among football players.

"I interned for an orthopedic surgeon for three summers while I was in college," Niswanger said. "I had a lot of fun doing that, and saw a lot of interesting surgeries. But football is what I really want to do. It's where my passion is."

So he kept his teeth in the ankle of his dream. In Kansas City as an undrafted free agent, Niswanger fought and clawed and managed to hold onto one of the last spots on the roster. As a rookie, he was third-team center.

Last year he moved up to second-team. Now, with the Chiefs revamping their offensive line almost entirely, the would-be doctor is, finally, first-team.

The medical career that so many young people strive all their lives toward has become "a fallback plan."

So what does he like about football?

"To be honest with you, what is there not to like about football?" he replied, looking around as weary teammates trooped off the field following a practice that had lasted nearly 2 hours.

He began talking at a faster clip.

"I look at it as the sport of men, as the sport of passion. It's the sport of velocity and strength and violence, a controlled violence."

But those who see only violence are missing its best part.

"The important thing, the thing people don't realize, is the intellectual side of it," he said.

"If you can take a playbook that's four inches thick and not only memorize it, but memorize it in a way that when you get out there and you've got 90,000 people screaming, you've got people moving, you're sweaty, you're tired, your blood's pumping - and you still make decisions in the blink of an eye - that's intelligence.

"That's one of the aspects that really drew me to this game, especially the offensive line positions."

Niswanger's IQ is high, which is good. But so is his head, which is bad.

Most centers are in the 6-foot-1, 6-2 range. That's ideal for keeping low and getting that all-important leverage as they snap the ball and explode into would-be tacklers. It's a problem the 6-5 Niswanger has battled all his football life.

"Rudy's doing great. He's probably the smartest guy on this football team," said left guard Brian Waters, a three-time Pro Bowler. "Physically, you worry because he's so tall. But Rudy does a great job, he's flexible. He knows how to use his height to his advantage."

Waters, a former center, has carefully watched Niswanger's development.

"He's still got a ways to go," he said. "He's got to get some experience, but that's all going to come with games. He's a family guy who's going to be accountable. He's somebody you can trust. There have been some tall centers who were successful."

At this point in his life, Niswanger figures being a tall center is better than being a tall doctor.

"Football is a young man's game and I can only play it for so long. And if I'm blessed enough to have both a long football career and a medical career, that's great," he said. "But if I play long enough in the NFL and I don't feel that I'm young enough to go back to medical school, well, that's great, too."