After the chaos of 2020, which saw the most amount of changes that an original Formula 1 calendar had seen since the winter of 1995 when several venues had financial and safety issues hanging over them, Formula 1 is once again in a situation where no venue is guaranteed to host the Formula 1 circus for the second year in succession.

When Formula 1 announced the season's provisional 23 race calendar in November of 2020, many noticed that Vietnam, who were supposed to make their Formula 1 debut that year, were absent, with round four remaining vacant before the Vietnam Grand Prix was shelved permanently for the time being because of corruption charges involving Nguyễn Đức Chung, chairman of Hanoi's people committee and a key official organising the race.

More cracks began to show in the winter of 2021; Melbourne, which had set to kick the season off on March 21st, was rescheduled for November 21st and China, due to return to their Formula 1 calendar on April 11th, lost their round three slot and is still unconfirmed to return later on this season.

Even as late as two weeks ago, Formula 1's 2021 provisional calendar looked increasingly fanciful as rumours swirled that the Canadian Grand Prix looked set to be shelved due to it being considered too risky for public health reasons.

The Canadian Grand Prix was finally cancelled on April 28th to make way for a return to Turkey, which is Formula 1's third replacement race of the season and may not be the last as two more races are in grave danger of being dropped.

The first one is Mexico due to the Autódromo Hermanos Rodríguez being used as a field hospital for patients suffering from Covid-19.

With the situation still not looking good as the Mexican government struggles to contain a high death toll, it could mean that the Mexican Grand Prix remains off the calendar for another year as the circuit continues to be used to beat the country's battle with the virus.

There are also grave doubts over Brazil's future on the 2021 Formula 1 calendar, in what has been a turbulent year for Brazillian motorsport.

First, the race was suspended over an issue regarding public funds to secure the race. Then the endless tug of war between the cities of Sao Paulo and Rio de Janeiro on who would host the Brazilian Grand Prix going in favour of Sao Paulo after Rio's project backed by Liberty Media and the country's controversial hard-right president Jair Bolsonaro was scrapped after a change of local government.

Bolsonaro's lacklustre and puzzling leadership, which has included a slow vaccine rollout due to his scepticism of vaccines, may play a part in the race's complete removal from the 2021 calendar after Brazil's covid death toll became the second-highest behind the United States.

With that in mind, what are the options for Formula 1 if Brazil and Mexico are declared non-starters for 2021?

Daniel Ricciardo has expressed the idea of having an Australian Grand Prix doubleheader. Although he has jokingly proposed the idea to Fox Sports, it might have legs to it if the sport wants to make up for last year's farcical cancellation of the Australian Grand Prix just hours before the practice sessions were to commence.

The idea could work if the F1 personnel have to quarantine on arrival to the country with a doubleheader in Australia, potentially seeing another rollout of the Sprint races to make up for the cancellation of Brazil.

Germany has also raised their hand in hosting a race with the Nurburgring having a loose contract on the table to host a replacement race if needs be, with hopes raised after the circuit cancelled its Rock am Ring music event, which was scheduled for the weekend of the 11th-13th June meaning they had a spot free to host Formula 1 again.

However, after Turkey took Canada's slot of the 11th-13th of June along with a full calendar of events for the Nurburgring means that once again, Germany's Formula 1 hopes remain in the balance.

However, two potential venues might fill the void if Formula 1 elected to cancel both the Brazilian and Mexican Grand Prix's.

The first could see an extension to the European season by one week with a return to Estoril in Portugal for the first time since 1996, for the European Grand Prix.

Estoril could host the race on the weekend of the 17th-19th of September if there were an appetite by the teams to host another race in Portugal with fans to make up for Portimao being behind closed doors and with it being suitable for Grand Prix racing with its grade 1 status and warm climate making it a potential winner with fans and personnel alike.

The second venue could also be the season's first doubleheader held in the same country, with Dubai replacing Brazil as part of a middle eastern treble header to end the season with Saudi Arabia being bumped to the weekend of the 26th-28th of November, leaving the 5th December slot open for the Abu Dhabi Grand Prix.

Dubai could be Formula 1's money-making golden ticket after nearly 18 months of loss-making, with the prospect of it being a marketing dream due to Dubai being a popular holiday destination, and with Dubai Autodrome's facilities being state of the art along with a roller coaster circuit layout making it a potential classic in what may be a crucial race in the championship fight, and F1 may have just secured a home run of a race.

There may be more changes abound if Formula 1 elects to cancel its entire Asian tour for another year, with Jerez and Nurburgring potentially getting their chances to host replacement Grand Prix with the circus possibly heading back to Jerez, who take Singapore's slot on the weekend of October 3rd whilst Nurburgring host Formula 1 on October 17th in what could become another cold Eifel Grand Prix.

Whatever decision the sport takes on where it finishes the 2021 season, it must do it now so that teams and broadcasters can make arrangements in good time to arrange PCR tests and hotels if they want any chance of finishing a season with twenty-three race weekends completed.