Kokkinakis considered retirement many times as he battled debilitating shoulder, groin, pectoral, back, knee and elbow problems before a cruel bout of glandular fever ruled him out of the 2020 Australian Open.

But the 24-year-old now admits he also suffered badly from depression while contemplating life without tennis.

"Depression was a real thing. I'd walk into cafes and get really bad anxiety and I was, like, 'I've gotta get out of here'," Kokkinakis told the Ordineroli Speaking podcast.

"I'd just get really nervous, I could feel my heart racing. Real strange stuff, stuff that I'd never had growing up.

"No positive thoughts ever came in and if they did for a second it would switch back off really quick."

Kokkinakis made an emotional return to his home grand slam in Melbourne last month, winning his first match at the Australian Open in six years before pushing world No.6 Stefanos Tsitsipas in a five-set second-round thriller.

"I don't want to sound all doom and gloom here 'cause I'm good now," said the one-time Davis Cup hero.

"But, yeah, it was pretty grim for a while.

"It was strange. You can't see any positives or you can't see any good things at the end of the tunnel.

"So I think only people that have gone through that can kind of understand that.

"Even if there's good things right in front of you, you can't see that 'cause you're so locked and consumed into your own thoughts.

"It's a real dark place and I don't want anyone to go through it because as bad as the physical pain is the mental pain is way, way worse."

Australian Associated Press