Novak Djokovic lifts his US Open runner-up trophy alongside champion Daniil Medvedev after the 2021 final in New York
Djokovic is a three-time US Open champion, but lost in last year's final to Russia's Daniil Medvedev

Novak Djokovic wants to finish with the most Grand Slam singles titles.

At Wimbledon in July, the Serb won his 21st major title, leaving him one behind Nadal's all time record.

This year, he has missed out on opportunities due to his decision not to be vaccinations against Covid-19.

The nine-time Australian Open champion was unable to play in Melbourne and could also be missing at the US Open, although the 35-year-old recently said he had his "fingers crossed".

Can Djokovic play in the US Open?

No at this time.

The United States has not allowed non-vaccinated visitors to enter since October of 2021.

The US Centers for Disease Control and Prevention (CDC), which is the nation's health protection agency, requires a non-US citizen to show proof of being fully vaccined against Covid-19 before travelling by air.

Last week's Cincinnati Open and the Indian Wells and Miami Masters 1000 tournaments were stopped by the ruling.

Canada's ban on unvaccinated visitors prevented him from playing at the Rogers Cup in Montreal.

Watch: Novak Djokovic gave an exclusive interview to the BBC's Amol Rajan in February

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

He told a reporter at Wimbledon in June that he had not considered getting a jab in order to compete in the US.

Are the rules likely to change so he can play?

Unvaccinated US citizens will now be in line with those who are vaccine-free after the CDC relaxed some of its restrictions.

The CDC said it would work to align stand-alone guidance documents in a number of areas.

The CDC's website - on the page where the details of vaccination proof for visitors are outlined - says it is "reviewing this page to align with updated guidance".

Fans of the player hope that travel restrictions for unvaccinated visitors will be loosened before the US Open starts.

Since the CDC's rules allow unvaccinated Americans to travel overseas, many people have questioned the scientific rationale behind not allowing the Serbian tennis player into the US.

With a week to go until the Grand Slam tournament begins, there has been no further movement and time is running out for the Serbian player.

The world number six thanked fans for their support shortly after the creation of the petition that asked for him to play.

I await to hear if there is any room for me to travel to the US so I prepare as if I'll be allowed to compete. He wrote in a social media post that he was hoping for the best.

How have we got to this stage?

In February of this year, he said he was willing to sacrifice playing in the biggest tournaments to stick to his principles because he didn't want to be vaccine free.

He was deported from Australia after a high-profile court case about the validity of his visa.

He said he was trying to be in tune with his body as much as possible.

He said he had always been a great student of wellbeing, health and nutrition and that his decision had been influenced by the positive impact factors such as changing his diet and sleeping patterns.

He said he was not against vaccinations.

The US Open could be one of the last events where this is an issue for the former world number one, since most countries which host events have relaxed rules.

Around the BBC iPlayer bannerAround the BBC iPlayer footer