Rafael Nadal is adamant the Davis Cup and ATP Cup cannot co-exist.
The world No.1 insists he'll head to Melbourne in a positive frame of mind despite suffering a ninth consecutive hardcourt beating at the hands of reigning Australian Open champion Novak Djokovic.
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But he's not so optimistic about the future of the sport's two biggest teams' events, pleading with tennis chiefs to unite and create one World Cup.
The inaugural 10-day, 24-team, $22 million ATP Cup staged in Sydney, Brisbane and Perth started just 40 days after Nadal helped Spain win the revamped six-day, 18-nation Davis Cup finals in Madrid.
"Is a long competition. Is a tough way to start the season. I don't know," Nadal said when asked to assess the ATP Cup.
"I think it is a great competition, but at the same time I can't change my mind that two World Cups in one month is not real. So is not possible.
"So we need to find a way to fix it and we need to find a way to make a big deal with ITF and ATP to create a big World Team Cup competition, not two World Cups in one month.
"I think that's a confusion for the spectators, and we need to be clear in our sport.
"And for the health of our sport and for the benefit of our sport it is, in my opinion, mandatory that we fix it."
After succumbing 6-2 7-6 (7-4) to Djokovic in a rematch of their 2019 Australian Open final, Nadal opted out of Sunday night's deciding doubles rubber, which Djokovic and Victor Troicki won 6-3 6-4 over Feliciano Lopez and Pablo Carreno Busta.
The 19-times grand slam champion said he was fatigued after a draining workload of six singles and two doubles matches in nine days, including three round-robin ties in Perth before jetting across the country to Sydney for the finals.
"I have been playing a lot of tennis the last couple of days. My level of energy is a little bit lower than usual because I played long yesterday, very long before yesterday, very long in Perth the last day," Nadal said.
Nadal’s horror run against Djokovic
The top seed certainly won't be underdone when he arrives at Melbourne Park.
But he's now lost 19 straight sets against Djokovic on hard courts in a barren run stretching back to his last victory over the Serb on the surface in the 2013 US Open final.
Not that Nadal was openly alarmed, the 33-year-old saying he was pleased with his trademark fight having played consecutive three-setters against David Goffin and Alex de Minaur the two nights before.
"Novak played, I think, an amazing first set, serving huge and putting a lot of pressure," he said of his latest defeat.
"But I did the most difficult thing. Changed a little bit the dynamic of the match after that first set. Happy the way that I was able to compete.
"And knowing that the last couple of days have been tough, I am happy the way that I managed to compete well in the second set.
"I had my chances. I was very close. Not happy with the loss, of course, but the feeling in that second set is positive."
Nadal unhappy with Sydney crowd
Serbia's stirring fightback, after Roberto Bautista Agut had put Spain 1-0 up in the best-of-three tie with a 7-5 6-1 win over Dusan Lajovic in Sunday night's opening match, left Djokovic's army of red, white and blue followers in the stadium overjoyed.
"Novak, Novak, Novak," they chanted after their hero rallied from a service break down in the opening set of the doubles to reel off six successive games to seize command of the final.
While Nadal pulled out of the doubles, there was no stopping Djokovic despite the world No.2 carrying Serbia with a similar twin workload.
Appearing for the first time in Sydney in a decade, the 16-times grand slam champion said he'd never played in such an atmosphere as he had in front of fervent Serbian fans over the past three days.
Even Nadal, one of the most popular athletes on the planet, found the going too much, complaining to the chair umpire and then giving Serbian spectators a sarcastic thumbs up after dropping serve to fall 5-2 behind in the opening set.
"Honestly, the crowd was fantastic every single day but sometimes people from some countries, they probably don't understand how the tennis goes," Nadal said.
"They think it's about football or this stuff and atmosphere in tennis is different, no?
"The respect for the players should be there, and at some point I think the respect with small part of the crowd have been not there."