The United Cup is not drawing the crowds organisers had hoped for, with a mixed reaction from Australians.

The event, with $15 million in prize money, is being played across Brisbane, Perth and Sydney, with a poor turnout in Brisbane, but a decent crowds in Sydney.

Played over 10 days, the 18-country tournament is missing several world stars, with the better event in Adelaide, where Novak Djokovic headlines the ATP 250 event.

Critics have already called the United Cup an event too far in a crowded New Year calendar at a time of year when most Australians are on holiday, with tennis not high on the agenda.

The calibre of player in Adelaide for the ATP and WTA tournaments is high.

Holger Rune, Jannick Sinner and Felix Auger-Aliassime are also in South Australia.

The WTA 500 is high in quality as well, with 2017 Wimbledon champion Garbine Muguruza former US Open champion Bianca Andreescu and world No.2 Tunisia’s Ons Jabeur among participants.