(Reuters) – Novak Djokovic said he is preparing for the U.S. Open as if he will be allowed to compete at the hardcourt major, despite his refusal to take the COVID-19 vaccine. Djokovic, who has three U.S. Open titles, will not be able to participate at this year’s U.S. Open due to current rules under which travellers seeking to enter the U.S. have to be fully vaccinated and provide a proof before boarding flights. Earlier this month, the 35-year-old was included in the entry list for the Aug. 29-Sept. 11 Grand Slam in New York. “I am preparing as if I will be allowed to compete, while I await …