Djokovic is only interested in tennis' biggest prizes. He still has the game to win them, but at age 37 his body is letting him down

Then there’s his diet and his specially designed shoes. A number of times he has hauled a personal hyperbaric chamber to a grand slam tournament and lately he has been exposing the benefits of a “magnetic disc” he carries around.

Novak Djokovic is 37 and was forced to stop playing because of an injury at two of the past four Grand Slam tournaments.