Nick Kyrgios has opened up about his return to tennis, his battle with alcohol, and his belief in conspiracy theories in a wide-ranging interview with British broadcaster Louis Theroux.

Warning: Readers please be advised that this story deals with examples of self harm.

The 29-year-old also spoke revealingly about his constant battle with his mental health, and why he has an issue with playing for Australia in a revealing conversation with Theroux on his eponymous podcast.

Kyrgios has not played a singles match on the ATP Tour this year, and only managed one in 2023, a straight sets defeat to China's Yibing Wu.

Injuries to his knee and wrist have ravaged the former world number 13 and Wimbledon finalist, marring a talent that seemed destined to bring the divisive character enormous success.

He said that he worked "10 times harder than the majority of people" to achieve what he has in the sport. 

Kyrgios has targeted a return to action for the Australian Open, but told Theroux that there were conditions to his return.

"I could come back now and beat 50 per cent of players," Kyrgios said.

"But I don't want to do that … Because my fans deserve a better version of myself that I am now on the court.

"I don't want to just participate."

Andy Murray's travails 'just not worth it'

Kyrgios points to his long-term rivals Rafael Nadal and Andy Murray as being examples of how not to drag their careers out.

Murray, who retired after the Paris Olympics following a career in which he won three grand slam singles titles, two Olympic gold medals and the Davis Cup, prolonged his career following hip surgery in 2019 that he felt could have ended his career.

Twenty two-time grand slam champion Nadal has said he will retire later this year, but has not been competitive since 2022.

"I look at how Andy Murray's doing it now, and how Rafael is going out, I don't want to be like that either," Kyrgios said.

"I don't want to be crawling to the finish line, in a sense. 

"What Andy Murray's achieved in this sport is second to basically no one, like, unless you're Novak [Djokovic], [Roger] Federer, or Nadal.

"Like, the next person is Andy Murray. 

"It's like, you've achieved everything, you deserve to go out, I think, a little bit more gracefully than he's done. 

"I think, that the surgeries, the pain, it's just not worth it, in my opinion."

Despite saying he wants to return, Kyrgios is under no illusions that the expectation that has followed him throughout his career — and the associated pressure — will instantly be heaped back on him.

"I know the world's not going to be nice on me when I come back, they're going to all of a sudden forget that I was out for a year and a half with injuries," he said.

"They're just going to think that it's Nick Kyrgios that has all the expectation again. So when he loses, it's not OK."

Kyrgios speaks up about 'dark time' in his life

That pressure has taken its toll, with Kyrgios speaking revealingly about the depression he suffered throughout his career.

"I was just struggling with who I was," Kyrgios said.

"It was hard at that time and I didn't feel like I could take a step back from the sport and kind of work on myself and get myself in the right headspace. 

"I was just playing and playing and playing and kind of dealing with everything. 

"And it was a dark time. Like I was drinking and I was spiralling out of control and I was continuing to play and travel. It was a lot."

He told Theroux he used to "drink like a fish" and have "20 to 30 drinks" before playing the next day, claiming he would give Nadal "a good run for his money".

That "hectic" period of Kyrgios's life saw him self-harm, wearing a long sleeve so he could continue to play without it being noticed, although he noted that British former world number one Murray did notice and ask him about it.

"It was horrible. I mean, I almost like kind of enjoyed feeling that way — and that's when I knew I had to get out of it," Kyrgios said.

He said that he spent time in a clinic, but only one night as he was due to play Rafael Nadal the next day.

Kyrgios said he was not in a good place, even now. 

"I fight it most days. Like, I don't wake up feeling amazing … I feel like I know my steps to get me out of my bad thinking now," he said.

"I feel like I could go back into those habits in an instant. That's how it feels. 

"I feel like I could do those things, but I don't want to. Like, before, I didn't have any resistance. I don't want to do that now."

'The most racist thing I've ever heard in my life'

Kyrgios has not played Davis Cup for Australia since 2019, although he has competed in other team-based events such as the Laver Cup and ATP Cup.

He notably turned down the chance to play Davis Cup under Lleyton Hewitt in 2022, opting instead to play an exhibition tournament in Saudi Arabia, the Diriyah Tennis Cup.

Kyrgios was heavily criticised for that, with there being a suggestion that he was more content lining his pockets than representing his country.

But he said the issue was far more deep-seated than that, noting Australia's problem with racism.

"One of our sporting legends told me and my family to go back to where we came from," Kyrgios said, with Theroux noting that person was Olympic swimming legend Dawn Fraser.

Fraser made the comments on Channel Nine in 2015 after Kyrgios was widely considered to have "tanked" during his Wimbledon defeat to Richard Gasquet, branding the Aussie a "disgrace".

Fraser apologised after Kyrgios labelled her "a blatant racist". 

"It's arguably the most racist thing I've ever heard in my life. Of course there's racism [in Australia]," Kyrgios said.

"How am I going to go represent a country that one of our greatest sporting ambassadors tells you that?"

'You're insane'

Away from the very serious nature of the chat, Kyrgios entertained conspiracy theories.

He argued with Theroux that the prospect of people moving large blocks of stone on logs was one of "insanity".

"How is that possible they got every measurement correct and they're all aligned?" Kyrgios said.

"And they did it with rolling large stones on logs is an insane statement. 

"Why are the doors so big? Like who needs to walk through the doors if they're that big? 

"I don't know who it was. I just don't think that we were capable. 

"It's 2024 and we can't even all get along. And you think that we built the pyramids? You're insane. That's insanity stuff."

He added that he has "thoughts" on the Moon landing and refused to state that the Earth was round.

"I'd probably be inclined to saying it's round, but I'm also not surprised if it was the other thing either," he said.