Head-to-head ties in what was previously the World Group were done away with in 2019, replaced by a group stage at a centralised location and one block of tennis to determine the winner from 18 teams.

Group action is split across Spain, Austria and Italy this year, with six group winners and the two best runners-up reaching the quarter-finals.

The Davis Cup Finals were also delayed from 2020 until this year because of the COVID-19 pandemic.

Spanish team mebers of Pablo Carreño Busta, Carlos Alcaraz and Albert Ramos-Vinolas are all in the top 50 of the men's singles rankings and are backed up well by veterans Feliciano López and Marcel Granollers as they bid to retain the tile Spain won in 2019.

Tennis great Rafael Nadal is a notable absentee, however.

Group A will not be easy for the hosts as they take on the Russian Tennis Federation (RTF), who boast four players in the top 30, led by world number two and US Open winner Daniil Medvedev. 

Andrey Rublev is ranked fifth in the world, while Aslan Karatsev and Karen Khachanov will prop up the squad.

Ecuador join Spain and the RTF in that group.

Also playing in Madrid is Group B, comprising Canada, Kazakhstan and Sweden.

Alexander Bublik of Kazakhstan is the top-ranked player at world number 36, while experienced Canadian Vasek Pospisil will hold his team's hopes on his shoulders.

Canada are shorn of young stars Denis Shapovalov and Felix Auger-Aliassime.

Groups C and F are to be played in the Austrian city Innsbruck, with the former featuring France, Britain and the Czech Republic.

Arthur Rinderknech is the top-ranked singles player for the French, who have doubles specialists Nicolas Mahut and Pierre-Hugues Herbert in hand, as well as Adrian Mannarino and Richard Gasquet.

Despite missing two-time Olympic champion Sir Andy Murray, Britain's squad has formed nicely in time for the tournament, with top-30 players Cameron Norrie and Dan Evans leading the charge with doubles technicians Joe Salisbury and Neal Skupski.

Austria face a difficult challenge to get out of Group F, with the hosts taking on Novak Djokovic's Serbia and a German side with three top-100 players including Jan-Lennard Struff.

Olympic champion Alexander Zverev declined to play for Germany, claiming the new format is not "the real Davis Cup".

Austria will not have the backing of a home crowd, as spectators have been banned as the country battles a rise in coronavrius cases.

The United States have a strong group of three players in the top 40 in the form of John Isner, Reilly Opelka and Frances Tiafoe in Group E in Turin, where they face tough opposition from hosts Italy, who bost top-10 player Jannik Sinner, as well as top-40 players Lorenzo Sonego and Fabio Fognini.

Colombia complete the group. 

Finally, Group D consists of Australia, Croatia and Hungary.

Marin Čilić holds Croatian hopes, while Alex de Minaur is Australia's top player.

Competition is to run until December 5, with quarter-finals scheduled from from Monday (November 29) to December 2, followed by semi-finals on December 3 and 4 and a final the following day.

The entire knockout stage will be played in Madrid.