The top men’s tennis player in the world, Novak Djokovic, spent Orthodox Christmas in an immigration detention hotel in Australia on Friday as he sought to fend off deportation over the country’s COVID-19 rules and compete in the Australian Open. Djokovic received calls from his native Serbia, including from his parents and the president, who hoped to boost his spirits on the holiday. On Instagram, he posted: “Thank you to the people around the world for your continuous support. I can feel it and it is greatly appreciated.” The 34-year-old athlete was barred from entering the country late Wednesday when federal border authorities at the Melbourne airport rejected his medical exemption to Australia’s strict COVID-19 vaccination requirements. He has been confined to the detention hotel in Melbourne pending a court hearing on Monday, a week before the start of the tournament, where he is seeking to win his record-breaking 21st …