Serena Williams said Saturday she is pressing ahead with plans to play in the US Open despite a wave of player withdrawals from the upcoming Grand Slam event over coronavirus fears.

The 23-time Slam winner returns to tennis next week at the inaugural Top Seed Open WTA event in Lexington, Kentucky, relaunching her season after a six-month hiatus caused by the COVID-19 pandemic.

Williams, who was one of the first players to commit to the US Open despite the pandemic, said her plans remain unchanged, adding that she was tentatively planning to go to Europe for the rescheduled French Open.

"I see myself doing it all if it happens," Williams said when asked about her schedule during a virtual press conference on Saturday.

"But I am not planning for the future, as tournaments got cancelled I was just like, 'Let me just work on today and see what happens.'"

The former world number one said she has spent the past six months at her home in Florida, sheltering from the threat of the coronavirus.

Williams has a history of pulmonary embolisms which have restricted her lung capacity, a factor which she said had prompted her to be a "little bit of a recluse" this year.

"I started social distancing in early March," she said. 

"I don't have full lung capacity so I'm not sure what would happen to me. 

"I am sure I would be okay but I don't want to find out.

"I have like 50 masks that I travel with, I don't ever want to be without one. 

'A little bit neurotic' 

"With health concerns I am super careful with what I have been doing and everyone in the Serena bubble is really protected.

"It is cool to play tennis, but this is my life and my health, so I have been a little bit neurotic but that is how I have to be right now."

Williams revealed that she had been practicing on her own court, built with the same hardcout surface used at the US Open. She has also stayed fit with construction of a home gym.

"I had to make a gym and my husband made a court for me. The gym is not quite done. The tennis court is fun, I go there and it is my own sanctuary. It's like, 'Why haven't I done this 20 years ago?'," she said.

Williams, who is also scheduled to play the Western and Southern Open tune-up event in New York before the US Open, admitted that only tournament play would allow her to properly gauge her fitness.

"Everyone has an opportunity to be more fit now, because we spent so much time at home to work on ourselves," Williams said.

"Fitness wise, there is going to be a tonne of fitness, but match fitness is different to fit-fitness."

Williams, who turns 39 in September, meanwhile said she was unable to say whether she would be at the rescheduled Tokyo Olympics in 2021.

"That is just looking too far ahead, I don't know if Tokyo plans to be in Tokyo, we will have to wait and see," she said.

"I don't know what to expect. One thing I have learned is don't plan, I am living for the day and for the moment, in a good way but I am not making plans too far out."