Novak Djokovic cast doubts over his return to the French Open next year after a shock loss to Brazilian teenager Joao Fonseca, 19,  in the third round of this year’s tournament on Friday.

Fonseca produced a sensational comeback to erase a two-set deficit and beat the Serbian 24-time Grand Slam champ 4-6, 4-6, 6-3, 7-5, 7-5. Asked if he would be back next year, Djokovic twice replied: “I don’t know,” but he was gracious in defeat, accepting he was outplayed on the night.