Novak Djokovic admits he was not "the favourite type of guy" for many of his rivals early in his professional career, including Roger Federer.
Key points:
- Djokovic feels he rubbed Federer the wrong way early in his career
- But Djokovic says he has always respected his opponents
- Djokovic believes there is a "line" players shouldn't cross in terms of their behaviour
It often appeared Djokovic's relationship with Federer was prickly when the Swiss was on the ATP Tour, perhaps not surprising given the competitiveness of their rivalry.
They first met on court in 2006 when Federer was at the peak of his powers and Djokovic was just shy of his 19th birthday.
Federer defeated Djokovic the first time they faced each other in a final of a major at the 2007 US Open, but the Serbian would go on to claim a 27-23 advantage in their career head-to-head meetings.
He is chasing a record 25th major singles trophy at the Australian Open, while Federer finished his career with 20.
Djokovic, a 10-time Australian Open winner, feels his personality rubbed Federer up the wrong way when he was starting out on the tour.
"I know certainly Federer didn't like the way I was behaving at the beginning," Djokovic said after beating Tomás Martín Etcheverry in the Australian Open third round on Friday night.
"I think it didn't sit with him well. I don't know about the others.
"I guess I wasn't the favourite type of guy to some of the top guys because I was not afraid to say that I want to be the best player in the world.
"I was confident and I felt like I have the game to back it up."
While highlighting his confidence, Djokovic says he "never, ever lacked respect" for his opponents.
"Whenever I start a match, before the match or finish the match, I would always greet the opponent, always acknowledge [them]," he said.
"Respect is something that I was taught that needs to be present, regardless of what is happening.
"Obviously on the court a lot of things can happen in a kind of heat of a battle. It was very long time ago now, 20 years since I made my debut, I think, on the professional tour.
"It's really hard to say who liked me more or less. I think I named one, so I don't know. I can't recall others."
Djokovic calls for greater respect
Alongside his stranglehold of the world number-one ranking, 36-year-old Djokovic is among the elder statesmen on the ATP Tour.
At last year's US Open, he seemingly took offence to Ben Shelton's trademark 'hanging up the phone' celebration when he mimicked the young American during their semifinal, which he won in straight sets.
He raised the issue of Shelton's on-court behaviour in an interview with French publication L'Equipe prior to the Australian Open, claiming the 21-year-old needed to show greater respect.
Speaking in Melbourne, Djokovic says he applauds the confidence of young players but warns there is a point where it can become disrespectful.
"I support 100 per cent a young player coming out on the court, like (Dino) Prižmić did the other night against me, and Shelton is doing coming out believing in his capabilities that he can challenge the best players in the world," Djokovic said.
"I don't dislike that at all. But there is obviously some kind of line, a non-visible line, of acceptable behaviour, I guess, towards the other player.
"If a player steps over that line, then obviously it starts being annoying. That's when you react or you don't react, whatever. It just depends.
"But I'm all for young players showing confidence and speaking, always with respect, towards the older guys who are on the tour."
Djokovic and Shelton had been on course to set up a re-match in the fourth round in Melbourne.
But the 16th-seeded Shelton, an Australian Open quarterfinalist last year, lost to France's 20th seed Adrian Mannarino 7-6 (7/4), 1-6, 6-7 (7/2), 6-3, 6-4 after almost five hours on court in their third-round clash.