Djokovic's secret weapon is a green disk

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 tennis 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.

The 37-year-old showed off the dinner-plate-size disc in a video on Instagram. "It's (an) energetic disc, creates an electromagnetic field around it and (the) kind of secret is in this pattern," he said.

"And so when you place it on a certain part of your body ... for example, if you have stomach issues, which I do have often when I'm nervous, stressed before the match, or indigestion issues, that creates heat."

"So then it starts enhancing the metabolic functions or it reduces inflammation."