Kansas City, Mo. ? If Whitey Herzog were commissioner, a unique walkaway clause in Mike Sweeney’s new contract might not pass muster.

“I don’t think they should allow clauses in multiyear contracts like that,” said the former manager of the Kansas City Royals and St. Louis Cardinals.

“It could open a can of worms.”

In an apparent first for baseball, Kansas City gave Sweeney the right to void the last three years of a five-year, $55 million extension he signed last month if the team fails to reach .500 in either 2003 or 2004.

It was a promise to do everything possible to build a competitive team. It was also the only way for the Royals, who haven’t had a winning season since 1994 or been in the playoffs since 1985, to retain their best player.

But many observers, publicly and privately, wonder if such a clause could have the unintended consequence of putting a player’s best interests at odds with those of his team or at least appearing to do so.

Taken to the extreme, what if a player with the “Sweeney clause” should play poorly in the final games of a season as his team falls below .500 and he becomes a free agent?

“Perception is often reality,” said agent Randy Hendricks. “A guy could be out there playing his heart out. But there will always be people who will assume the worst. On the other hand, it keeps a player with the team and it also invites him to be a leader on the team.

“And nobody would ever doubt Mike Sweeney’s integrity.”

The Royals are still waiting on final approval of the contract. But before completing the deal last month, they ran it past the commissioner’s office.

“The player relations committee has been made aware of it,” said Royals general manager Allard Baird. “We haven’t gotten anything back yet.”

The fact the commissioner’s office has not acted does not necessarily mean anything because such procedures routinely take several weeks.

“If there was a problem, I would have hoped there would be some response by now,” said Baird.

Opt-out clauses are not uncommon. Catcher Charles Johnson had one linked to the Florida Marlins’ commitment to build a new stadium.

“This works entirely in the favor of the player. I would not be at all surprised if all agents will want something like that now for the players,” said Herzog. “In negotiations today, once somebody gets something, the next guy wants it. Every have-not ballclub could be in the situation.

“Then just about the time they’re putting a competitive team together, a guy might take a walk.”

Michael Weiner, associate general counsel of the players’ association, wasn’t sure how many teams might take the same approach.

“I can see it benefitting players and I can set it benefitting clubs,” he said. “Mike Sweeney got what he wanted, a substantial multiyear commitment and protection for himself where he doesn’t have to play for a second-division team for the next five years.

“And I can see a club using it to their benefit by saying, ‘Look, I’m going to offer you less guaranteed (money), but I’ll give you the Sweeney clause.’

“Frankly, there are a lot of teams out there where this kind of clause just wouldn’t make sense.”