Novak Djokovic, one of the greatest players in tennis history, has hinted at how he envisions his retirement, but the timeline for stepping away from the sport remains uncertain.

The Australian Open is set to begin and a host of players will be competing for glory at the first Grand Slam of the year.

Novak Djokovic is undoubtedly one of the biggest tennis stars of all time. Across his 22-year career, Djokovic has won an incredible 99 titles and has earned an estimated $185 million in prize money. His best year came in 2011, when the 24-time Grand Slam champion won 11 titles and picked up an impressive $18.2 million in prize money alone.

Australian Open begins January 12 in Melbourne, and the draws for the men’s and women’s singles are intriguing — and have thrown up some blockbuster first-round matches. The Athletic’s tennis writers,

- Italy’s Jannik Sinner returns the ball to Netherlands’ Tallon Griekspoor during the Davis Cup final tennis match between Netherlands and Italy at the Martin Carpena Sports Hall in Malaga, southern Spain,

Novak Djokovic is set to compete at the Australian Open for the 20th time in his career. Here is what's at stake at his most successful grand slam.