Kyrgios out of AO with injury

Nick Kyrgios pulled out injured from the Australian Open (AO) on Monday without hitting a ball, saying he was "devastated" to miss his home Grand Slam.

The talented but temperamental Australian, considered an outside chance of winning the title, had struggled with an ankle issue leading into the event.

But it was knee discomfort that forced the Wimbledon finalist out, a day before he was due to face Russian Roman Safiullin in the first round. He will require minor surgery.

Kyrgios was also planning to defend his doubles title alongside Thanasi Kokkinakis.

He joins a growing list of players to withdraw from the opening Grand Slam of the year, including men's world number one Carlos Alcaraz and two-time women's champion Naomi Osaka.

"I'm devastated, obviously," he said at a hastily arranged press conference at Melbourne Park, describing the pain as a "constant throbbing".

"I've had some great tournaments here, winning the doubles last year and playing the tennis of my life probably going into this event.

"I'm just exhausted from everything, and (it's) obviously pretty brutal. One of the most important tournaments of my career. It hasn't been easy at all," he added.

"There's a mixture of emotions... just bad timing, but that's life. injuries are part of the sport."

His physio Will Maher said a scan showed a cyst as a result of a small tear in his lateral meniscus, but it was not a career-threatening injury.

Kyrgios's team used a charity match against Novak Djokovic on Friday to test out the injured knee and the Australian "didn't pull up great".

"He still tried to give himself every chance in the following days to have subsequent training," said Maher. "But it was clear that with each passing session that he was getting sorer and sorer."