Many fans were excited about a potential match between Djokovic and Shelton at the Australian Open. The two were projected to meet in the fourth round of the Grand Slam if they both won their first three matches.
However, that contest will not be happening because an inspired Adrian Mannarino defeated Shelton in the third round. It was an excellent match that went to five sets, but that will be no comfort to the American.
Djokovic's and Shelton's fourth round meeting would have been a rematch of their US Open semifinal, where the Serbian imitated Shelton's signature celebration after winning the encounter in straight sets.
Djokovic said he did this because he lacked respect, but Shelton refused to get dragged into those claims. However, in a press conference after his third-round win, Djokovic made it clear that he has no issue with the 21-year-old's confidence.
"As far as Shelton's level of confidence and coming out, I don't mind that actually at all. You got to believe. I'm all for that."
The 10-time Australian Open champion then explained that while he thinks confidence and self-belief are a good thing, there is a line where behavior becomes disrespectful towards other players.
"But there is obviously some kind of line, 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 don't react, whatever."
Djokovic ended by speaking more generally about younger players and how he is in favour of them showing confidence.
"But I'm all for young players showing confidence and speaking, always with respect towards the older guys who are on the tour, but being confident in themselves and their tennis."