Petra Kvitova has said she knows players who may not compete at the US Open next month due to Covid-19 and has even cast doubt on her own participation.

The Grand Slam event will begin on August 31 in New York and will be a behind-closed-doors tournament.

She told BBC 5 Live: "I know a few players will definitely not go if the restrictions are like they are now. 

"I'm still thinking of what everything will look like, what the restrictions will be, how many people we can take and if they quarantine us."

Stars such as Novak Djokovic and Rafael Nadal have cast doubt on their own attendance. Players are unsure due to the Covid-19 outbreak in the country and their own countries protocols.

The US have recorded 3.4 million cases and 136,000 deaths as a result of the disease, according to John’s Hopkins University.

However, stars are competing at other competitions before the US Open.

Kvitova is playing in the Bett1 Aces in Germany currently which is the first event to return in the country with spectators. Crowds have to socially distance in the stands.

And Serena Williams and Sloane Stephens will return to court in the Top Seed Open in Kentucky which begins on August 10.

It is one of two events, the other being held in Prague, added to the WTA tour which will restart on August 3.