Nick Kyrgios urged Novak Djokovic to stay in tennis "as long as possible" after the Serbian great Tuesday pulled out of his only lead-up tournament to the Australian Open, saying he was "not quite physically ready".

Serbian great Novak Djokovic Tuesday pulled out of the Adelaide International, saying he was "not quite physically ready" as prepares for the Australian Open.

Novak Djokovic, has decided to pull out of next week's Adelaide International, the build-up event for the year's first Grand Slam tournament, the Australian Open.

Explaining his decision to quit PTPA, Novak Djokovic said: "my values and approach are no longer aligned with the current direction of the organization."

Novak Djokovic, the undisputed king of men's tennis with a record 24 Grand Slam titles, opened up in a refreshingly honest manner about the challenges of breaking into the sport's elite level during the height of the Roger Federer-Rafael Nadal rivalry.

Former British tennis great Andy Murray said Monday he was "disappointed" with Novak Djokovic's results while coaching his former rival.

Novak Djokovic won the 101st title of his career when he came from behind to beat Lorenzo Musetti 4-6, 6-3, 7-5 in the final of the ATP event in Athens on Saturday.

Novak Djokovic cruised into the Athens ATP final with a 6-3, 6-4 victory over Yannick Hanfmann on Friday.

Novak Djokovic returned after three weeks out of action to ease past Alejandro Tabilo in straight sets at the Athens ATP tournament on Tuesday.

Novak Djokovic announced on Tuesday he would miss the upcoming Paris Masters, but added he hoped to compete at the tournament next year.