EXCLUSIVE: Tennis star Novak Djokovic working out ahead of the US Open later this month. The Serbian icon looked fit and healthy and donned a mask after his run in the sunshine in Marbella. Spain. He has been regaining health after returning a positive Covid-19 test in June, and is now stepping up his training. Djokovic was forced to issue an apology for the conduct of his Adria Tour fiasco after becoming a victim himself by testing positive for coronavirus. The world No 1, who organised the event, where social distancing was widely ignored, softened an earlier statement in which he had shown little remorse for what transpired. Djokovic headlines the initial men?s singles entry list for the 2020 US Open. Djokovic, a three-time US Open champion, leads an entry list that includes seven of the world?s Top 10 men, who are set to compete Aug. 31-Sept. 13 at the USTA Billie Jean King National Tennis Center in Flushing, N.Y. 06 Aug 2020 Pictured: Novak Djokovic. Photo credit: MEGA TheMegaAgency.com +1 888 505 6342