The Australian Rugby League (ARL) has not yet signed off on taking part in the tournament against Great Britain and New Zealand again in 2005.
The ARL had planned to support the event again next year, but chief executive Geoff Carr said from England, where this year's tournament is taking place, that he wanted to judge the impact on the players before there was a final commitment.
"We're very wary of the fact our elite players already play a lot of football," Carr said.
"We don't want to kill our guys off and we'll largely be guided by what they say at the end of this tournament.
"If they come back home and say, 'we've had a great time, let's do it again', we would have no problem with next year.
"If they come back and say, 'we've had a gutful, we need a break from touring', we would certainly take that into account.
"There is nothing contractually to commit the ARL to an annual series at this stage."
Various clubs, whose other players have started or are about to begin pre-season training for next year, are concerned their star players still have not finished last season because the Tri-Nations event goes on for so long.
Brisbane chief executive Bruno Cullen said it was important to keep international league going "but I don't think they should put this type of event on every year. The players will get sick of it".
"It's a long, long tour coming at the end of a long season and I don't think you can ask the players to try to rise to that level at this time every year," Cullen told League Correspondent "It will lead to more players deciding to retire from representative football."
Penrith general manager Mick Leary said he was keen to raise the issue at the league's annual conference, which will be held in Sydney on December 8-9.
"My question is: do we need to have it every year?" Leary said.
"I know we need to do what we can to promote the game in England, but we have to consider the players and the toll on them."