The nine-time Australian Open champion reacted angrily to doubts surrounding his left hamstring, which has proven an obstacle throughout the tournament in Melbourne.
Djokovic has been seen nursing the problem area, while also taking medical timeouts during his second and third-round matches.
A more ruthless display against Alex De Minaur in the fourth round, dropping just five games, saw the Serbian media ask him about those sceptical about the severity of his injury.
Djokovic said: “I leave the doubting to those people – let them doubt. Only my injuries are questioned. When some other players are injured, then they are the victims, but when it is me, I am faking it. It is very interesting. I don’t feel that I need to prove anything to anyone.”
Djokovic has fuelled discussion with players opining on the issue and Fritz has backed the former world No 1 but insists some players do exaggerate their injuries.
“My opinion that probably nobody cares about... 80 per cent of players are always dealing with something (severity levels differ) but everyone is honesty always a little banged up,” Fritz said. “The media is only ever focusing on the top guys so there issues get more attention.
“Also some players are more vocal talking about injuries then others. I don’t think people fake injuries, I do think sometimes players stretch the severity of the injury because it depressurizes them and helps them play better (which honestly is fine, do whatever works).
“I don’t think it’s done in a bad sportsmanship kind of way, and before people get defensive, I’m not talking about anyone in particular this is just what I see as a player, sometimes there r serious injuries, sometimes there over exaggerated ones from people 1-500. I’m not taking shots at any players so please don’t get defensive.”
Meanwhile, Djokovic has also threatened to release documents to prove the severity of his injury.
“I have got the MRI,” Djokovic added. “Ultrasound and everything else, both from two years ago and now. Whether I will publish that in my documentary or on social media depends on how I feel. Maybe I will do I it, maybe I won’t.
“I am not really interested at this point what people are thinking and saying. It is fun, it is interesting to see how the narrative surrounding me continues, (a) narrative that is different compared to other players that have been going through similar situations.
“But I am used to it and it just gives me extra strength and motivation. So I thank them for that.”
The incident adds to a history for Djokovic and pushing through the pain barrier, having overcome an abdominal muscle injury against Fritz two years ago before going on to win the title.
Djokovic also appeared in big trouble in the 2015 final in Melbourne against Andy Murray, but eventually overcame the issue to triumph.
There was a retirement during the Wimbledon quarter-finals in 2017 because of an elbow problem, while at the US Open in 2019 a shoulder issue led to him pulling the plug in the fourth round.
His last defeat in Australia, in the fourth round against Chung Hyeon in 2018, meanwhile, prompted him to undergo elbow surgery.
Djokovic may be hinting at preferential treatment for rivals such as Rafael Nadal, who ended the French Open last year on crutches because of a chronic foot problem and was widely praised for his efforts in winning another title.
Djokovic and De Minaur have a problematic relationship after the Australian’s reaction to his attempts to play the Australian Open last year.
De Minaur complained about the deportation saga taking attention away from other players, and said: “As well as every other tennis player, if you wanted to come into the country, you had to be double vaccinated. It was up to him, his choices, his judgment.”
Speaking about the Australian, Djokovic said: “I respect him as a rival, a colleague, as I respect everyone. I have no problem contacting him, congratulating him, etc. But I don’t have any other relationship. I don’t have any communication with him. He showed in 2022 what he thinks about me.”
Asked about Djokovic’s injury, De Minaur said: “I think everyone’s kind of seeing what’s been happening over the couple weeks. It’s the only thing everyone’s been talking about.
“I was out there on court against him. Either I’m not a good enough tennis player to expose that, or it looked good to me.”
The 23-year-old then clarified his comments on social media: “I hate how media will always create controversy and takes things out of context to make a headline,” he wrote. “Got outplayed and outclassed yesterday. How about we focus on the tennis for once. I will get back to work and improve you can count on that. Thank you Australia.”
PA contributed to this report