World number one Novak Djokovic said he does not have "much respect" for outspoken Australian star Nick Kyrgios away from the tennis court.
Kyrgios has been critical of Djokovic in an ongoing feud with the 17-time grand slam champion, who was labelled a "tool" by the former following a list of requests made to Tennis Australia (TA) and the Victorian government for tennis players stuck in hotel quarantine amid the coronavirus pandemic.
Former world number 13 Kyrgios was also critical of Djokovic's decision to stage the Adria Tour in Europe last August – in the midst of the COVID-19 crisis – having previously dubbed the Serb star "cringeworthy".
Djokovic rekindled his rivalry with Kyrgios after being asked about the 25-year-old on the eve of the Australian Open.
"I've said this before," Djokovic told reporters on Sunday. "I think he's good for the sport. Obviously he's someone that is different. He goes about his tennis, he goes about his off court things in his own authentic way.
"I have respect for him. I have respect for everyone else really because everyone has a right and freedom to choose how they want to express themselves, what they want to do. My respect goes to him for the tennis he's playing. I think he's very talented guy. He's got a big game. He has proven that he has a quality to beat any player really in the world in the past.
"Off the court, I don't have much respect for him, to be honest. That's where I'll close it. I really don't have any further comments for him, his own comments for me or anything else he's trying to do."
Djokovic has won the past two Australian Open finals as he eyes a record-extending ninth Melbourne Park crown.
The 33-year-old, who opens his title defence against Jeremy Chardy on Monday, has won the Australian Open every time he has reached the semi-finals.
Djokovic has reached at least the semi-finals in seven of his last nine grand slam tournaments, winning five of them.
No male has won more Australian Open men's singles titles than Djokovic, who said: "It's a love affair. Probably something similar maybe not like Rafa [Nadal] has with the French Open, but I've been feeling more comfortable on the court each year that I've been coming back.
"The more you win, obviously the more confidence you have and the more pleasant you feel on the court. It just feels right. If you're in the right state of mind, regardless of the surface, you have a better chance to play at your best.
"When I stepped on the court this year for the first time in the practice session, I relived some of the memories from last year, also the other years that I won the tournament here.
"It just gives me great sensation, great feeling, confidence. It feels right. It feels like the place where I should be and where I have historically always been able to perform my best tennis. Hopefully can be another successful year."
Asked if he still feels nerves, Djokovic – who is looking to close the gap on Rafael Nadal and Roger Federer (both 20) for the most slam trophies – added: "Every match, every match. Every single match. I don't want to speak on behalf of the other athletes, but I just feel like it's almost impossible to eliminate that kind of pressure, anticipation, the nerves coming into any match really for an athlete. At least in my case.
"It's just that I managed over the years to train myself, I think with the experience and with also the dedication that I had off the court to the mental preparation, that helped me react better to those kind of emotions. Sometimes I don't manage to overcome the pressures and the stress and nerves. Sometimes I do. It really just depends. Even though I've been blessed to experience a lot of success, especially here in Australia, but also in my career. I still feel that those failures, if you want to call them that way, even though I don't believe in failures, I just believe in opportunities to improve, kind of the lessons to be learned, but in those matches you lose, big matches, that's where you learn the most.
"That's where you're facing the kind of wall mentally. You're upset. You have a lot of different things happening, and you feel like you let yourself down. That's where it's the biggest opportunity for you to really address that and become stronger, more capable. You can get to know yourself a little bit on deeper levels. It still happens to me.
"Every single tournament, regardless of my previous success, of course I do feel that I have more confidence, more experience, maybe more training in understanding how to deal with these specific situations when I'm coming on the big court, being expected to win 99 per cent of the matches that I play.
"But it's still there. It's still there. I don't think it's ever going to go away. Especially when the occasion is big, when you're playing for the biggest trophies."