Tennis star Novak Djokovic faces a further slip down the world rankings after pulling out of the Indian Wells and Miami Open tournaments due to American rules forbidding unvaccinated foreigners to enter the country.
Djokovic, 34, lost his place at the top of men's pecking order last month after his defeat in the quarter-final of the Dubai Open.
Daniil Medvedev, who reached the final of the Mexican Open, dislodged him to become the 27th number one since the rankings were computerised in August 1973.
The 25-year-old Russian will begin the Indian Wells tournament as top seed. Should Alexander Zverev win the crown in California, the 24-year-old German would pocket 1000 points and knock Djokovic from second place.
Djokovic has won the Indian Wells and Miami competitions 11 times during his illustrious career.
As two of the season's nine Masters, they are considered the most prestigious events on the circuit after the four Grand Slam tournaments in Melbourne, Paris, London and New York.
While I was automatically listed in the @BNPPARIBASOPEN and @MiamiOpen draw I knew it would be unlikely I’d be able to travel. The CDC has confirmed that regulations won’t be changing so I won't be able to play in the US. Good luck to those playing in these great tournaments 👊
— Novak Djokovic (@DjokerNole) March 9, 2022
Djokovic was unable to play at the Australian Open in January after falling foul of the country's visa regulations.
During a legal battle to gain entry, his hitherto private medical files - outlining that he had not been vaccinated against the coronavirus - were unveiled in court.
Djokovic says he has accepted that his desire to remain unvaccinated will harm his prospects of playing at certain tournaments.
In his absence, attention will fall on Medvedev and his compatriot Andrey Rublev who is ranked seventh in the world.
Just after the Russian president Vladimir Putin ordered his country's troops into Ukraine, the pair spoke about their hopes for peace.
Rublev wrote: 'No war please" on one of the TV cameras by the court after one of his wins in Dubai.
On social media, Medvedev said: "I want to speak on behalf of every kid in the world. They all have their dreams, their life is just starting, so many nice experiences to come: first friends, first great emotions.
"Everything they feel and see if for the first time in their lives. That's why I want to ask for peace in the world, for peace between countries.
"Kids are born with inner trust in the world, they believe so much in everything: in people, in love, in safety and justice, in their chances in life.
"Let's be together and show them that it's true, cause every kid shouldn't stop dreaming."
