Novak Djokovic has revealed a new secret weapon that he credits with helping keep him healthy and prolong his career — a green “energetic disc”. 

Known for his new-age spiritual interests, the Serbian star is in Melbourne hoping to wind back the clock and win an 11th Australian Open and record 25th Grand Slam singles title. To help achieve the feat, he has a device made by an engineer in Serbia he claims has helped him deal with several ailments.