Controversial tournament struggling to sell tickets despite big names

Davis Cup organisers admit selling tickets for the revamped competition is proving a challenge with less than two weeks to go.

Eighteen national teams, including Australia, will head to Madrid for the first edition of the week-long, World Cup-style event, which begins on November 18.

ALL CLASS: Ash Barty’s stunning act of generosity after record windfall

The new format, which has largely replaced the traditional home-and-away fixtures, was controversially approved at last year's International Tennis Federation AGM despite vociferous opposition from a number of current and former players, officials and fans.

Barcelona footballer Gerard Pique's Kosmos company is the financial muscle behind the event having pledged to invest $3US billion ($A4.3 billion) over 25 years.

The new revamped Davis Cup tournament, which Novak Djokovic and Rafael Nadal will take part in, is struggling to sell out. (Getty Images)

But efforts to recoup some of that money through strong ticket sales are proving problematic, although hosts Spain's group ties, against Russia and Croatia, have sold out the main arena, which seats more than 12,000 spectators.

Nadal and Djokovic named

The disappointing sales come despite countries naming strong teams, which was the main objective of the change of format.

Australia, captained by Lleyton Hewitt, are placed in Group D alongside Belgium and Colombia for the finals.

Nick Kyrgios will make his first Davis Cup appearance since February last year, alongside Australian No.1 Alex de Minaur, Jordan Thompson, John Millman and doubles specialist John Peers.

Six of the top 10 will be competing, including world No.1 Rafael Nadal and Novak Djokovic, with Germany's Alexander Zverev the only eligible player to opt against making the trip.