Organisers have also said everyone who visits the Indian Wells Tennis Garden in California must be vaccinated, adding a further question mark over Djokovic's participation.

The Serbian is unvaccinated and was deported from Australia earlier this year because of his vaccination status, following a drawn-out legal saga.

Djokovic has therefore played only one Association of Tennis Professionals (ATP) tournament this year.

Djokovic has now dropped to world number two - overtaken by Russian Daniil Medvedev, who will be able to compete at Indian Wells as a neutral - and gets a bye into the round of 64 as the second seed.

The winner of a match between Belgium's David Goffin and Australia's Jordan Thompson is due to play Djokovic on Saturday (March 12).

The Indian Wells Masters is an ATP 1000 tournament, while the women's event is likewise a Women's Tennis Association (WTA) 1000 tournament.

Briton Cameron Norrie is the defending men's champion, and the field includes German Olympic champion Alexander Zverev, who has escaped a suspension for repeatedly striking the umpire's chair at an event last month.

Spain's Rafael Nadal - like Djokovic a 20-time Grand Slam singles champion - is the fourth seed.

The standout match in the first round of the WTA event pits Japan's Naomi Osaka against American Sloane Stephens.

Both are Grand Slam winners - Osaka having done so four times.

Osaka also won at Indian Wells in 2018.

Spaniard Paula Badosa is the defending champion and gets a bye into the second round.

Czech top seed Barbora Krejčíková has withdrawn through injury, while world number one Ashleigh Barty of Australia is also not playing.

That leaves Aryna Sabalenka - playing as a neutral as players from Belarus must do, like Russians, because of the invasion of Ukraine - the top-ranked athlete in the field.

The women's first round of a hard-court event often dubbed tennis' "fifth major" begins tomorrow, with the finals set to be played on March 20.