De Villiers was formerly non-executive chairman of the ATP

Speaking after taking up a dual role of chairman and president of the ATP, South African Etienne de Villiers said the issue was "unbelievably complex".

But he said: "I'm convinced the calendar is too long. We will shorten it. We're locked into 2007 and need a proper vision to implement in 2008."

The Australian Open was hit by the withdrawals of injured trio Marat Safin, Andre Agassi and Rafael Nadal.

And five players pulled out of November's end-of-season Masters Cup, which was supposed to showcase the ATP's top eight players.

The WTA, which runs the women's tour, has also come under fire after injuries to many of its top players.

We got to all work together, the ATP, the ITF, the WTA too Roger Federer

De Villiers continued: "We're trying to figure out what makes sense, where to place the emphasis, whether we should combine events and if so, how many.

"It's clear though that we need to restructure the current calendar because it is not efficient. It needs to be addressed by all partners."

World number one Roger Federer welcomed De Villiers' involvement and encouraged the ATP, WTA and ITFm, which runs the Davis Cup and Grand Slams, to work together.

"We can always discuss scheduling. But you have to take things a little bigger and further," he said.

"What's the plan for the next five, 10 years, 20 years? The players who are around right now should give back to their game.