The AFL's longest-serving coach, Mick Malthouse, says player calls for free agency should be resisted for the sake of maintaining an even competition.

The Collingwood coach says giving senior players the chance to join the team of their choice risked creating a league dominated by a select few clubs.

"If we had free agency, would we start to get back to what we were in the '60s and '70s where four clubs dominated the competition because they had the money and all the clout?" Malthouse asked on the AFL website.

"Unfortunately, I've got to say that will take place."

The AFL Players' Association (AFLPA) has been campaigning for a limited form of free agency and says it has almost unanimous backing from the players.

The association wants players with seven years of service to be able to move to the club of their choice.

The AFLPA used St Kilda midfielder Luke Ball's failure to get his wish to join Collingwood in October's trade period to help justify their push.

But Malthouse said the fact that 23 other players had managed to switch clubs indicated it was not needed, urging AFL football operations manager Adrian Anderson to "hold firm".

"This year has been an extraordinary year in player movement," Malthouse said.

"So free agency, in effect, can be almost put on the backburner because of the sheer numbers that have changed clubs.

"I'm at the end of my career, but I want to see this game develop and be the greatest game. The only fear I have is a two-tiered system which could develop from a free agency factor."

The AFLPA has argued that the salary cap and a limit on the size of clubs' player lists will ensure the evenness of the competition is not jeopardised.

Malthouse, who will enter his 26th season as an AFL coach in 2010, added there were aspects of trade week he did not like, saying it "brings out the worst in people".

"Unfortunately I've been involved in it from the word go. I've never seen it change," he said.

"There are too many suspicions, too many undertone whisperings ... everyone wants a $10 player and only wants to give $5 up."