United Cup tweaked as players mull Australian options

It means countries will battle over one session in a men's and women's singles and mixed doubles, rather than across two days when a reverse singles rubber was included in the tournament's debut.

Teams have also been reduced to a maximum of three men and three women.

Eighteen countries will contest the second edition from December 29, with semi-finals and the final in Sydney on January 6-7.

Players have until October 17 to commit to their country's campaign, with $15 million in prize money another lure.

But the prospect of playing a traditional lead-up tournament in Brisbane - to be contested at the same time - could be more appealing.