But that is obligatory for any non-US citizen wishing to enter the country.

Djokovic did not take his name off the entry list before Tuesday's draw, and tournament organisers admit they have not yet been able to find out whether he has a viable route into the US.

"Novak Djokovic is on the tournament entry list, and therefore is placed into the draw," the BNP Paribas Open said in a statement.

"We are currently in communication with his team; however, it has not been determined if he will participate in the event by getting CDC (Centers for Disease Control and Prevention) approval to enter the country. We will provide updates in the future as we learn more."

The BBC has also approached his management for information.

There are very few exceptions to US Covid entry requirements, and it seems unlikely Djokovic has recently had the vaccine.

He was deported from Australia in January after the government cancelled his visa in a row over his vaccine status, and Djokovic told Amol Rajan last month that he is prepared to miss other big events in future.

"The principles of decision making on my body are more important than any title or anything else," he said.

"I'm trying to be in tune with my body as much as I possibly can."

As the second seed in Indian Wells, Djokovic has a first-round bye and so would not play his first match before Saturday.

He may be hoping there is a change in the US entry rules in the next 48 hours, but if he does have to withdraw then the balance of the draw will be affected.

The seeded players are spread out across the 96 man field, and if Djokovic's name is later removed, that section of the draw will be weaker than the others.

Andy Murray is a potential beneficiary. The former world number one will play a qualifier in the opening round, but would be a potential third-round opponent for Djokovic.

Britain's defending champion Cameron Norrie has a first-round bye, but finds himself in the same quarter of the draw as the world number one Daniil Medvedev and the fifth seed Stefanos Tsitsipas.

Dan Evans, the 27th seed, also has a first round bye.