39-yr-old Djokovic to feature at Swiss Indoors Basel after 15 yrs. Twenty four-time Grand Slam champion Novak Djokovic will compete at the Swiss Indoors Basel in October after receiving a wild card for the ATP 500 event. The 39-year-old will make his fourth appearance at the tournament and his first since 2011. The Serbian tennis player won his 102nd tour-level title and first of the season earlier this month in Beijing.