Polish world No. 4 Agnieszka Radwanska and this year's Wimbledon semi-finalist Jerzy Janowicz were announced as the top-seeded team Tuesday for the 2014 Hopman Cup in Australia.

It will be Poland's first appearance at the mixed-team December 28-January 4 tournament in the western city of Perth, and they earned their number one ranking ahead of American pair John Isner and Sloane Stephens.

But in a blow to organisers, popular duo Novak Djokovic and Ana Ivanovic, this year's runners-up to Spanish champions Anabel Medina Garrigues and Fernando Verdasco, will not be back, with Djokovic committed to taking part in the Davis Cup final.

French pair Jo-Wilfried Tsonga and Alize Cornet are seeded third with Spain's Tommy Robredo and Medina Garrigues the lowest-ranked of the eight teams.

Tournament director Steve Ayles said he was confident Djokovic and Ivanovic would be back in Perth in the future.

"I know that they believe they have unfinished business, and that's the sort of carrot we will be using. And of course when Novak has played here he's always gone on to play well at the Australian Open," Ayles said.

"We will always be approaching marquee players to come and play at the Hopman Cup, but the other thing is that we do make sure we have a strong, even field."

Teams (in order of seedings)

Jerzy Janowicz/Agnieszka Radwanska (POL)

John Isner/Sloane Stephens (USA)

Jo-Wilfried Tsonga/Alize Cornet (FRA)

Milos Raonic/Eugenie Bouchard (CAN)

Radek Stepanek/Petra Kvitova (CZE)

Andreas Seppi/Flavia Pennetta (ITA)

Bernard Tomic/Sam Stosur (AUS)

Tommy Robredo/Anabel Medina Garrigues (ESP)