U.S. Open champion Daniil Medvedev said on Sunday that he was eager to play in the Australian Open in January but could not confirm his participation if only players who have been vaccinated against COVID-19 are allowed in Melbourne.

Victoria's premier Daniel Andrews said this week that no unvaccinated players would be permitted to play in the tournament despite Prime Minister Scott Morrison earlier telling local media they could compete but only after undergoing a two-week quarantine.

Medvedev refused to disclose his vaccine status and said he preferred to keep his medical records private, a stance similar to that of world number one Novak Djokovic.

"I always said it, that I really like Novak's answer about this. I want to keep my medical, no matter if it's about vaccine, leg injury, head injury... I want to keep my medical private for a reason," said the world number two ahead of the Paris Masters.

"I feel like tennis is such a brutal sport where you're always one on one against your opponent, and any information you give him can go against you.

"If you're playing Australia, it's obvious you're vaccinated. So that's why I said I'm willing to play Australia, but I won't say if you'll see me there, but we're going to see in January."

Djokovic, returning to action in Paris for the first time since his loss in the U.S. Open final, said he would wait for Tennis Australia to confirm what the rules will be on quarantines and vaccinations before he makes his decision on whether to chase a record 21st Grand Slam title Down Under.

"Right now we don't have any official announcement or statement," said Djokovic. "So until that's out, I won't be talking about this anymore.

"When official condition requirements to travel to Australia and play in Australia are out, then obviously I'll see what I personally do with that, and also the bigger group of the players because the situation is obviously different in Australia than most parts of the world."

Medvedev, who will finish the year following the conclusion of the Davis Cup Finals in December, also called for administrators to shorten the length of the season and reduce the workload of players.

"We're probably the only top sport that is playing 11 months a year... so you're going to have like two-and-a-half weeks (after the Davis Cup) of the off-season to prepare for Australian Open, which is obviously not enough," he said.

"So it's a very tough topic where I could speak for hours, and I actually have no real answer, but, yeah, it would be better if the season would be a bit shorter."