By Ian Ransom
MELBOURNE (Reuters) - After a wildly successful debut in 2020, the ATP Cup kicks off in more subdued circumstances in Melbourne on Tuesday with Novak Djokovic looking to get champions Serbia off to a flying start against Canada in the truncated team-based event.
Last year's tournament featured 24 nations and played to packed houses across the country, but the upcoming event has been reduced to 12 teams and all the action will be confined to Melbourne Park due to COVID-19 biosecurity measures.
Crowd capacity for this year has been capped at 25%.
The competition will nonetheless provide a form guide for next week's Australian Open, with most of the Grand Slam's top male contenders representing their nations after a mandatory 14 days in quarantine.
Djokovic, unbeaten in eight ties, was majestic in last year's tournament as he fired Serbia to a 2-1 victory over Spain in the final, including a straight sets win over Rafa Nadal.
There will be no easing in for the world number one as he faces Canada's rising talent Denis Shapovalov at Rod Laver Arena in their Group A clash, a moutwatering rematch of last year's quarter-final.
The 21-year-old Shapovalov, long tipped for Grand Slam success, pushed Djokovic to a third-set tiebreak last year and will be eager to see if he has closed the gap on the Serb.
Nadal will headline the evening session at Rod Laver Arena when he takes on home hope Alex De Minaur, a year after overhauling the Australian 4-6 7-5 6-1 in the semi-finals.
"(We will) try to give to the fans around the world and the fans here in Australia a good show," Nadal said on Sunday in a preview of his Group B encounter.
"For some of the people who are suffering a lot at home, we will try to (provide) good entertainment for them."
U.S. Open champion Dominic Thiem, who gave Djokovic a scare in last year's Australian Open final, tops the bill at the John Cain Arena, formerly known as Melbourne Arena, when the Austrian plays Italy's world No. 10 Matteo Berrettini in Group C.
World number four Daniil Medvedev leads a powerful Russian team with Andrey Rublev and will start his tournament against Argentina's Diego Schwartzman with a Group D match in the night session at John Cain.
Germany, Greece, France and Japan join the fray on Wednesday.
World number seven Alexander Zverev, who crashed out of last year with serving problems, leads Germany again and will start his tournament on Wednesday against Shapovalov.
(Editing by Peter Rutherford)