Safina has enjoyed her most successful year on the tour in 2008
Dinara Safina has warned of a possible WTA Tour boycott by leading players over changes to the schedule.
The Russian, who will rise to a career-high ranking of two in the world on Monday, said players are unhappy with the WTA's '2009 Roadmap Calendar'.
"If they don't listen to what we have to say we might even choose to boycott the new tour," said Safina.
She added: "No one seems to understand which tournaments you can play and which you can't."
The new schedule aims to give players a "healthier calendar" with a longer off-season and less changes of surface.
It will see 26 tier one and tier two events combined into 20 Premiere tournaments, with players committed to play in at least 10.
Four £2.6m tournaments in Indian Wells, Miami, Madrid and Beijing will be mandatory for all players who qualify.
Below the mandatory events will be five £1.2m events in Canada, Dubai, Rome, Cincinnati and Tokyo, of which the top-ranked players must play at least four.
The WTA has committed to having at least seven of the world's top 10 players at each of these events. Players will complete their schedules by competing in at least one or two £400,000 events.
"They said the leading players would have to play in designated tournaments while lower-ranked players would be able to enter any event they like," said Safina after losing to fellow Russian Vera Zvonareva at the Kremlin Cup in Moscow on Saturday.
"There's no logic in that at all. What if all the top players choose to enter the same tournament? What will the WTA do then? We want to know. There are a lot of grey areas."
Former US Open champion and world number two, Svetlana Kuznetsova, agreed with her compatriot.
"I was told only two players from the top 10 could enter a smaller tournament like the Kremlin Cup next year," said the current world number seven.
"What if Jelena Jankovic and Serena or Venus (Williams) want to play here?
"Then all the top Russian players, and there are five of us in the top 10, will not be able to play in their home tournament. That's nonsense."