Four-time grand slam winner Kim Clijsters says she remains determined to revive her career after years away from tennis, even as the coronavirus outbreak seeds uncertainty in the professional schedule.

Former world No.1 Clijsters and 2017 US Open champion Sloane Stephens are among the headliners as World TeamTennis kicks off its three-week regular season on Sunday, at the Greenbrier resort in West Virginia.

Clijsters’ 2020 comeback after nearly eight years away from the sport was put on abrupt hold in March due to the COVID-19 outbreak, but she told reporters on Wednesday the hiatus has not diminished her desire to be on the court.

“The most important lesson for me, is to just kind of trust the process,” said Clijsters, who lost to Briton Johanna Konta in the first round of the Monterrey Open four months ago.

“It doesn’t mean because COVID happened that I’m not interested in playing more tennis,” said the 37-year-old, who spent part of the coronavirus hiatus in New Jersey and part in her native Belgium.

“There are some challenges and combining parenting at home and teaching the kids at home and still going to practice and things like that, so it was challenging but at the same time you get through that together.”

The competition comes weeks after a handful of top players, including world No.1 Novak Djokovic, tested positive for COVID-19 after the second leg of the Adria Tour in Croatia, prompting widespread criticism of the event.

WTT says it has several precautions in place to minimise the risk of COVID-19 exposure, with all players and staff having self-quarantined for two weeks in the United States. Players must undergo testing and have daily temperature checks.

No more than 500 fans are allowed at the Greenbrier’s 2,500-seat stadium, Centre Court at Creekside, and all are required to wear masks and undergo temperature checks.