ATP Cup kick-start for tennis summer January 02, 2020 by AAP / Glenn Cullen

SYDNEY, AAP - The big four may have been reduced to the terrific two but there's still enough star power for the inaugural ATP Cup to make a fresh mark in Australia's summer of tennis.

Starting on Friday and played across Sydney, Brisbane and Perth before the finals in the Harbour City, the men's teams event has a couple of big things going for it in world No.1 and No.2 Rafael Nadal and Novak Djokovic.

The pair won't be joined by 20-time grand slam winner Roger Federer (withdrew citing family reasons) and the other member of the once-fabled quartet, Andy Murray (injured).

But with young guns like Daniil Medvedev, Stefanos Tsitsipas and Alexander Zverev on show the line up remains impressive for the Australian Open tune-up.

Effectively replacing three decades of the Hopman Cup mixed teams event, Brisbane International men's event and the Sydney International in the January calendar - that latter of which struggled to attract a strong men's field - the ATP Cup may take some bedding in.

Coming just six weeks after the revamped Davis Cup teams event, which featured 18 teams contesting a finals tournament in Spain, all it could be seen as overkill.

Canadian up and comer Denis Shapovalov thought as much, suggesting the two events should merge in future.

"I think the timing is interesting. I think it is a little bit strange to have it at a similar time as Davis Cup," he said on Wednesday.

"It is a weird feeling playing a world championships then coming into another event that is pretty much the same thing."

Djokovic already raised concerns about the two teams events co-existing but the likes of German world No.7 Zverev said he was a big fan of the new competition.

Defending Australian Open champion Djokovic will be based in Brisbane with his fellow Serbs for the round-robin phase alongside seven other teams, including Australia, who are headed up by Alex de Minaur and Nick Kyrgios.

With Nadal in Perth with Davis Cup champions Spain alongside the likes of Medvedev's Russia, it leaves Sydney short on talent until the knockout phases when the NSW capital hosts the last eight teams.

While teams can nominally get by with two players for the matches which include two singles clashes and a doubles fixture each, they can call on up to three more participants.

That opens the door on some key players sitting out ties or individual rubbers, the counterpoint being they'd still be available for later fixtures if their team was still involved.

Some new technology will be used at the event, including an artificial intelligence system that players and coaches can use for analysis. Video reviews include six dedicated cameras for detecting foot-faults and team zones will replace the player chairs near the umpire, allowing on-court coaching.

The winner will be decided on January 12 in the final at Sydney Olympic Park Tennis Centre.