MELBOURNE, Dec 22 (Reuters) - Australian Open chief Craig Tiley is confident Rafa Nadal will be at Melbourne Park for next month"s Grand Slam despite testing positive for COVID-19, but he is still uncertain whether Novak Djokovic will be playing. Nadal caught the novel coronavirus while playing in an exhibition tournament in Abu Dhabi last week and said he would make a decision on his future tournaments depending on his "evolution" over the weeks ahead. read more "I"m confident Rafa will be here," tournament organiser Tiley said of the 20-times Grand Slam champion at Melbourne Park on Wednesday. "Players that are testing positive now will complete a period of time until they are no longer infectious and they will be fine. If you are going to test positive and you want to play the Australian Open, your timing would be now." Tiley reiterated that all players and staff at the Australian Open would be vaccinated or have a medical exemption granted by an independent panel of experts. read more Those requirements have prevented Djokovic, who has declined to disclose whether he is vaccinated, citing privacy, from confirming whether he will bid for a 21st Grand Slam title and a 10th Australian Open crown next month. Tiley said that as far as he was aware, no players had yet been granted medical exemptions and that it would be up to Djokovic to disclose the grounds on which he gained entry to Australia. "If Novak shows up at the Australian Open, he"ll either be vaccinated or he"ll have a medical exemption," he added. "Medically, he doesn"t talk to anyone about it. I"m not going to ask Novak that, it"s none of my business. "I will know that (he fulfils) one of those conditions." Tiley said that if the world number one was going to play for Serbia in the ATP Cup in Sydney in the first week of January then he would be arriving with the first tranche of players next week. "We want to have the best players here, I"d love to have Novak here," he added. "If he meets those conditions then great, if not, it"s disappointing." Roger Federer, the other men"s player with 20 Grand Slam titles, and Serena Williams, who has won 23 Grand Slam titles, have already ruled themselves out of the tournament as they continue their recoveries from injury. Tiley also announced that former U.S. Open champion Sam Stosur and her fellow Australians Daria Saville and Maddy Inglis had been granted wildcards for the women"s singles draw at the Jan. 17-30 tournament.