It is still too early to write off the whole 2020 tennis season despite the coronavirus pandemic, according to ATP chairman Andrea Gaudenzi.
World number two Rafael Nadal recently said he would sign up to halting plans for any tournaments to be held this year in order to ensure the 2021 Australian Open can go ahead.
But Gaudenzi has not reached that point yet, saying it may be premature when playing without fans remains an option at a time the extent of future international travel restrictions is unclear.
"It would be unwise to call it quits now," he told reporters, per Sky Sports. "Nobody knows what will happen, we want to keep an optimistic overview.
"Obviously, there could be a subset of options, which is playing with closed gates or deciding how to deal with travel restrictions.
"But we have not made these decisions so far because they are all hypothetical scenarios."
Wimbledon has been cancelled, but the US Open is still scheduled for August 31.
The French Open was previously postponed from May until September, with organisers last week saying it could be played without fans and subject to a further delay.
"We have set a deadline of May 15 for the tournaments in July, post Wimbledon and June 1 for the tournaments in August," explained Gaudenzi.
"So we are, in principle, dealing it on I would say six to eight weeks in advance in time for making a decision. Longer than that, it would be foolish to make decisions in my opinion.
"The [US Open] announcement might be a little bit later, we don't know. Once we get to the beginning of June, we will probably know more about the US summer."
Gaudenzi concedes travel restrictions, and how they may differ across nations, is among the toughest challenges to solve.
"You can have an estimate that it's going to be fairly difficult and unlikely that all these countries will align to one single policy relating to travel restrictions," he said.
"Australia today for example is probably in a completely different phase than the United Kingdom. You look at Sweden, they have taken a completely different approach.
"So we could play a tournament in Sweden probably today. But can we travel 100 players to Sweden today? No. So that's the challenge."