Australian Open vaccination demand puts Djokovic defence in doubt

Novak Djokovic in action against Dominic Thiem (not seen) of Austria during Men's Singles Final match within the 2020 Australian Open at Melbourne Park in Melbourne, Australia. (Photo by Recep Sakar/Anadolu Agency via Getty Images)

Australian regulations requiring those entering the country to be double vaccinated against Covid-19 are raising doubts over the attendance of leading tennis players at January's Australian Open