KANSAS CITY, Mo. — In one sense, the possible departure of Pro Bowl defensive end Jared Allen would be nothing new for the Chiefs.

They've lost premier defensive players before. Just in the last several years, the Chiefs had to replace cornerstones such as Derrick Thomas, Neil Smith, Albert Lewis and James Hasty.

The difference is those players were at or near the end of their careers. The 26-year-old Allen, suddenly the subject of heated-up trade talks, is in his prime—and that may make him the most difficult to replace, if it came to that.

The Chiefs have talked with the Minnesota Vikings and Tampa Bay Buccaneers about a trade involving Allen, who led the NFL in sacks last season. Allen is in Minnesota meeting with the Vikings today, with a visit to Tampa possible as well."He was the most disruptive player on that defense, that's for sure," said former Chiefs quarterback Rich Gannon, now a game analyst for CBS. "The thing I really like about him is that he plays with a lot of energy and effort. He doesn't take plays off. He shows up in the running game. Those are things you like at that position. As a pure pass rusher, he runs the edge so well. It's hard to find guys who can do that.

"When you lose a player like that, you don't just find a replacement easily."

Allen, the Chiefs' franchise player, has wanted out of Kansas City since negotiations for a long-term contract broke down last year. He has indicated he will not sign a long-term contract with the Chiefs if the sides don't agree on a deal by July.

Allen had yet to discuss the particulars of a long-term contract with either the Vikings or Buccaneers. But a bigger obstacle could be an agreement between either team and the Chiefs on draft-choice compensation.

As the Chiefs' franchise player, Allen is free to sign a contract offer sheet with any other team. If he does, the Chiefs have the right to match the offer and retain Allen. If they declined to match, the Chiefs would receive two first-round draft picks in exchange.

It's unlikely that either the Vikings or Bucs would be willing to part with two first-round picks as well as satisfy Allen's financial demands with a long-term deal. But one team or both may be willing to part with a first-round and lower-round choice.

The NFL draft is April 26 and 27. The Vikings have the 17th pick in the first round, and the Bucs have the 20th pick. Minnesota has two third-round choices, including one obtained in an earlier trade with Denver.

If the Chiefs sent Allen to the Vikings for Minnesota's first- and initial third-round selections, that would give Kansas City two of the draft's top 17 picks and five of the first 73.

By merely engaging in talks with the Vikings and Bucs, the Chiefs have in effect indicated they would accept less than two first-round picks for Allen. It was unclear what changed the Chiefs' thinking in this regard, though they appear to have made little or no progress in negotiating a long-term contract with Allen.

The Chiefs were cautious about giving Allen a long-term deal last year at least in part because of his two DUI arrests in Johnson County. He served a two-game NFL suspension at the beginning of last season for violation of the league's substance-abuse policy and by all accounts appears to have changed his behavior in that regard.

In a statement released by the Chiefs, president/general manager Carl Peterson acknowledged discussions regarding a trade of Allen with teams he did not identify. A source indicated they were Minnesota, Tampa Bay and Jacksonville, though the Jaguars later backed out of the discussions.

"At this point," Peterson said, "all of these discussions are preliminary."

So depending on the developments of the next week, with the draft coming up, the Chiefs may be planning to select Allen's replacement. One of the draft's premier pass rushers, Ohio State's Vernon Gholston, was invited yesterday to Arrowhead Stadium to meet with the Chiefs.

The Chiefs could obtain a replacement pass rusher by drafting Gholston or another top defensive end, Virginia's Chris Long, with their first pick, which is fifth overall. They then could use the first-round pick obtained from Minnesota or Tampa Bay to draft an offensive lineman, another position of great need.

Though the unsigned Allen is a franchise player and technically available to the 31 other teams, the idea of him playing for any team other than the Chiefs next season had seemed farfetched. Few teams appeared willing to give the Chiefs two No. 1 draft picks, and the Chiefs had given no indication they would accept less.

So in that regard, yesterday's news was stunning. One Chiefs defensive player who did not wish to be identified was angry that the Chiefs would even entertain thoughts of trading their best defensive player and one who at 26 fits in nicely with their youth movement.

It's not often that a pass rusher in his prime moves from one team to another. In a sense, the Chiefs losing Allen would be like the Colts losing Dwight Freeney or the Dolphins losing Jason Taylor.

"Those guys have a little bit of a longer resume," Gannon said. "But you're on the right track. Jared Allen is still a dominant player at his position."

Losing Allen wouldn't necessarily gut the Chiefs' defense. But the cover 2 system favored by coach Herm Edwards is based on the ability to get pressure on the quarterback without having to blitz.

Achieving that goal wouldn't get any easier without Allen.

"He did everything for us," said former Chiefs defensive lineman Jimmy Wilkerson, who signed as a free agent last month with Tampa Bay. "Look at the numbers he put up in sacks, forced fumbles, tackles, percentage of playing time. All of that makes him a key player to that defense. Jared was the energy on the defensive line. He brought so much energy to the game that it motivated everybody else. If you lose him, that energy level isn't the same.

"It will take a while for them to get somebody through the draft or through free-agency who can do the things for them that he can do. I guess they have a plan. Every team we played against was worried about Jared Allen. They knew what he could do."

Unless the Chiefs hit it big in the draft, nobody on their defense will cause that kind of worry for opponents.

"It sets them back a few squares," Gannon said. "He's a cornerstone."

"Having said that, I kind of like the move. When you look at that team and where they're going, if they can get something for him, it's a great way to build for the future. I don't anticipate them going to the playoffs next year, with or without Jared Allen.

"There are a lot of other things that can go into it. They can look at his impact in the locker room, the practice field, the meeting rooms, the little run-ins he's had. You have to take all of that into consideration and ask, `Is this a guy who's going to continue to dominate for another five years, or has he kind of reached his peak?' I'm sure the Chiefs anticipate he'll be a great player next season, but what about the year after that?

"Maybe their answer is they're not sure and they should get something for him while he's hot. If that's the case, then you move him."