Nick Kyrgios says he is "devastated" to have pulled out of the Australian Open due to a knee injury, but knows he has made the right decision.
Kyrgios and his support team made the call on the first day of the Australian Open after an MRI showed a cyst caused by a small tear in his lateral meniscus.
His physiotherapist Will Maher said it was "impossible" to determine when the 27-year-old sustained the injury, but he "started to describe discomfort" in his knee in the past fortnight.
Kyrgios underwent treatment for the injury but decided against playing in the Australian Open as he was not confident he could play deep into the tournament.
He will return to Canberra at the end of the week to undergo an arthroscopic procedure.
Kyrgios announced his withdrawal at a hastily arranged media conference at Melbourne Park.
"This coming around is just bad timing. But that's life. Injury is a part of the sport," he said.
"I guess I can draw some inspiration from someone like Thanasi [Kokkinakis] who has had a bunch of injuries and has bounced back.
"Look, I'm not doubting I will be back to my full strength and playing the tennis I was playing prior to this event.
"I'm devastated, obviously. It's like my home tournament. I've had some great memories here.
"Obviously last year winning the title in doubles and playing the best tennis of my life probably, then going into this event as one of the favourites, it's brutal.
"All I can do now is just look forward, do what I need to do and come back."
Kyrgios was seeded 19th at Melbourne Park and was scheduled to play Roman Safiullin in his first-round match on Tuesday.
The Wimbledon finalist had not played a competitive match in the weeks leading up to the Australian Open after withdrawing from the United Cup and Adelaide International due to injury.
The Canberran played an exhibition match against nine-time champion Novak Djokovic on Rod Laver Arena on Friday night.
Kyrgios said he gave himself as much time as he could before deciding to pull out.
"I got off the court yesterday and was dealing with it, and we were going to make a call then," he said.
"I've worked so hard. Now, I've had the year I had last year and I'm back inside the [top] 20, being seeded at a grand slam [tournament], feeling as good as I'm feeling and playing the way I'm feeling.
"I wanted to give myself a chance. I had some hope. But after today, I hit with Thanasi, someone who's playing the way he's playing, and he pushed me around the court a little bit.
"It was easier to make the call today."
Kyrgios was set to play alongside Kokkinakis in the men's doubles at Melbourne Park, with the pair winning the title last year.
His withdrawal comes two days after Australian women's number one Ajla Tomljanović was also forced to pull out of the Australian Open because of a knee injury.
'Not a significant injury'
Maher said Kyrgios faced a "relatively straightforward recovery" and they were hopeful he would be back on the court for the Indian Wells Masters event in March.
He said it was just a "routine" MRI that confirmed the extent of the injury.
"It's not a significant injury in the sense that it's going to be career-threatening or anything like that," Maher said.
"Even at that stage, it was still worth persevering to see if we could do anything to get him back on court.
"To Nick's credit, he did try everything. Any amount of injections that he could try to get into his knee without causing long-term damage.
"We came to Melbourne with the hope there might be some pressure relieved from that procedure and he'd have some relief and be able to get up to a level he was comfortable to compete."
Maher said they used the exhibition match against Djokovic to test whether Kyrgios could compete potentially across two weeks of the Australian Open.
"He didn't pull up great and he still tried to give himself every chance in the following days to have subsequent training," Maher said.
"But it was clear that with each passing session that he was getting sorer and sorer."
Maher said they made the "sensible" decision to withdraw.
"At this stage, he wants to feel mentally comfortable that he can go seven matches, he can go the distance, and needs to be able to do potentially seven three-hour matches," Maher said.
"Getting on the court simply wasn't enough for him. The situation now is, we wanted to prevent him from having further injury or making that injury worse."
