RIVER FALLS, WIS. ? Two years after Kansas City drafted him in the fourth round out of a lower-division school, Jared Allen finally is learning how to play defensive end.

“And that’s a heck of a thing to say about a guy who already has 20 sacks,” noted defensive coordinator Gunther Cunningham.

Happy and high-spirited, Allen was full of joy just to be in the league during his first season. To the surprise of many observers who hardly expected big things from someone from Division I-AA Idaho State, he won a starting job before the season was halfway done.

He also wound up with nine sacks, a total exceeded among Chiefs rookies only by the late Pro-Bowler Derrick Thomas.

Then he was even better his second season. Able to bend his lanky 6-foot-6 frame and get great leverage coming off the edge, he had 11 sacks for a defense that finally began showing overall signs of improvement. Again, only Thomas had more quarterback takedowns his first two years in a Chiefs uniform.

Now in his third year, Allen is leaner and stronger and more confident – and smarter in the way he goes about things – than ever before.

“I want to go to the playoffs,” he said. “I want to go to the Pro Bowl. I want to go to the Super Bowl. I want all that stuff. So I’ve really focused this year on really honing down my skills. There are always individual games within the game. I worked a lot this spring. I’m in a lot better shape than I’ve been in a long time.

Kansas City Chiefs defensive end Jared Allen, right, twists away from the block of teammate Kyle Turley during drills at training camp. Allen was working out Monday in River Falls, Wis.

No, he does not figure this is the year to establish himself as one of the best defensive ends in the league.

“I think I already have established myself as one of those,” he said. “I think it’s a year for me to even establish myself as the best, as a player. There’s so much more I want to grow as.”

Whether he achieves that goal in the Chiefs’ revitalized defense remains to be seen. But Allen has been doing everything anyone could ask. A rigorous training program in Arizona brought him to training camp in great shape. His weight is up to 270 pounds, but he retains that lean flexibility that characterized his first season.

Plus, he has been studying his craft as though he were cramming for final exams, sometimes surprising even himself with how much more there is to know about the fine art of NFL defense.

“Every year I watch myself and see what I can do to take it a step higher,” he said. “There’s always something you can learn.”

Judging by the way he’s charging off the ball in the Chiefs’ first workouts in River Falls, all his hard work is paying dividends.

Kansas City Chiefs rookie free agent Nick Reid, center in red, sheds a block during morning practice. Reid, a Kansas University product, was working out Monday in River Falls, Wis.

“Jared has great passion for the game and desire. But he’s really improved,” Cunningham said. “It’s taken him two years to really become a better technical pass-rusher. Prior to this, he did it all heart and attitude. He would just fight you ’til he got there.”

His added maturity is also making him a leader, something no one might have imagined from the happy-go-lucky rookie of 2004.

“You wouldn’t believe it,” Cunningham said. “But he and I have a lot of conversations. A lot of in-depth conversations. That is the making of a good football team, when you have those kind of guys.”

Added Allen, “I’m expecting big things out of myself this year.”

Missing from camp Monday was the first-round draft pick who could wind up starting at the other defensive end. But Tamba Hali had a good excuse. He was back home in New Jersey finishing his test and paperwork to become an American citizen.

Hali, who played at Penn State, is a native of Liberia who fled that country’s civil war at the age of 10.

He was expected back in camp today.