Organisers of the Chinese GP admit it is "highly unlikely" the Shanghai event can take place as scheduled on 11 April.
We have reported that with Melbourne's season opener set to be postponed amid the ongoing covid crisis, the same is true for China.
"We are in contact with the leadership of Formula 1 by videoconference almost every week," said Yibin Yang, general manager of the race promoter Juss Event.
"It is highly unlikely that the race can take place in the first half of the year, in April. We hope to have it in the second half instead and have formally sent that request," he added.
"But if all international events are postponed to the second half of the year, the city simply will not have enough opportunities to hold them," Yang admitted.
"Activities such as this require the involvement of significant community resources, so there would be a shortage of resources and also conflicts in terms of marketing."
Roger Benoit, a veteran correspondent for Blick newspaper, claims F1 authorities are working on a plan for travelling members of the F1 circus to be vaccinated.
Haas boss Gunther Steiner thinks the 2021 season will begin, notwithstanding the likely postponements.
"I think Bahrain is going to happen," he said. "They did a fantastic job last year and when we got there we felt very safe."