Rafael Nadal starts his pre-retirement farewell tour against Carlos Alcaraz on Thursday at the Six Kings Slam, and Novak Djokovic faces Jannik Sinner at an exhibition event that awards money but no ATP ranking points and is Saudi Arabia's latest foray into tennis.

Widely considered one of the greatest rivalries in the history of the sport, Rafael Nadal and Novak Djokovic have met no fewer than 60 times, with their last meeting coming at Roland Garros in the second round of the singles competition during this summer’s Paris Olympics.

Rafael Nadal will clash with Novak Djokovic for the final time in his career at the Six Kings Slam on Saturday afternoon.