The former tennis coach left a lasting influence on the sportCHAMP LOST Nikola Pilić dead at 86: Grand Slam champion who led Wimbledon boycott and coached young Novak Djokovic passes awayTENNIS icon Nikola Pilic has died aged 86. The Croatian tennis star died on Monday, according to a statement released by the Croatian Tennis Association. 4 Tennis icon Nikola Pilic has died aged 86 Credit: EPA4 Pilic was a Grand Slam doubles champion and singles runner-up Credit: GettyPilic was a Grand Slam champion thanks to his success in the US Open doubles in 1970. His runner-up effort at Roland Garros came in the same year that he was a catalyst for the Wimbledon boycott. Djokovic, who first started coaching with Pilic aged 10, previously said: "Nikola is my tennis father.