Nick Kyrgios' Australian Open was over before it began after a frank conversation with his physiotherapist Will Maher.

The 27-year-old sensationally withdrew from the tournament on Monday because of a knee injury, just a day before he was due to play his first-round match against Roman Safiullin.

Only hours after Kyrgios to the court for a workout with doubles partner Thanasi Kokkinakis at Melbourne Park, Maher quizzed Kyrgios on whether he felt his knee could sustain two weeks of high-intensity tennis.

'Can you get through seven matches against these guys?,' the physio asked the Aussie firebrand.

'I can't do it,' was Kyrgios' reply, which left Maher no choice but to inform him he'd have to pull out of the tournament. 

The Australian came into the tournament nursing an ankle injury he picked up in Dubai last month.

And Maher told reporters on Monday that a routine MRI that was done after Kyrgios suffered discomfort in his knee revealed that he has a tear in his lateral meniscus and a cyst.   

'There’s a parameniscal cyst growing in his left meniscus, which is the result of a small tear in his lateral meniscus,' Maher said at a press conference just after the news broke on Monday afternoon.

'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, to the point even last week he was having a procedure called a fenestration and drainage where they use a syringe to try and drain the cyst, which Nick has some pretty gruesome photos of.'

Shortly after announcing his withdrawal, Kyrgios did indeed share a gruesome picture on Instagram of what had been drained from his knee. 

The injury isn't serious enough to be career-threatening and the Australian is scheduled to have surgery over the next two weeks. 

'I'm devastated, obviously, it's my home Grand Slam,' Kyrgios said.

'I'm just exhausted from everything. Pretty brutal, one of the most important tournaments of my career. Hasn't been easy at all.' 

Kyrgios reached the final of a Grand Slam tournament for the first time in July, losing in four sets to Novak Djokovic at Wimbledon, and was considered among the favourites to win at Melbourne Park.  

'It's my home tournament, I've had some great memories here,' he said.

'Obviously last year winning the title in doubles and playing the best tennis of my life, probably. 

'Going into this event as one of the favourites, it's brutal. 

'All I can do now is look forward, do what I need to do and just come back [...] Obviously a mixture of emotions [...] that's life. It's part of the sport.'