Nick Kyrgios took aim at John McEnroe after being informed that the American great had accused him of tanking in his five-set defeat to Andreas Seppi at the Australian Open.
Home hope Kyrgios blew a two-set lead to lose 1-6 6-7 (1-7) 6-4 6-2 10-8 to the Italian on Wednesday, having beaten Seppi in similar circumstances two years ago.
Having wasted a match point before losing the third set, Kyrgios smashed his racket against the floor in frustration and was unable to regain his composure in the subsequent two sets.
Kyrgios was banned from the ATP Tour for giving up on a match against Mischa Zverev in Shanghai last year and has been seeing a sports psychologist since to help him overcome mental issues.
And McEnroe believed he was seeing a similar pattern against Seppi, saying on commentary for Eurosport: "It's okay to show your emotions and I'd like to see that in a one-on-one game when you're out there by yourself, but when he goes through those periods when he's not competing, it's just a black eye for the sport. And it's a black eye for him."
Informed of McEnroe's criticism in his post-match news conference, Kyrgios said: "Well, my body was sore. I was hurting.
"Was it John McEnroe? Good on him. Great career. Good on him."
And the seven-time grand slam winner was a repetitive theme in the briefing from there.
Asked about a knee injury, Kyrgios said: "I don't know, mate. Ask Johnny Mac. He knows everything."
And prompted to explain whether he is consulting a psychologist at Melbourne Park, the Australian replied: "Johnny Mac will know, mate. Just talk to him. He knows everything."
After going out to Andy Murray at Wimbledon last year, Kyrgios questioned his own commitment to tennis and that issue again came to the fore.
He said: "I think I didn't have the best preparation. It's on me.
"I did a couple things in the off-season that I'm probably not going to do next time. It's on me, I guess. My body's not in good enough shape. You live and you learn.
"Maybe [I should] just not play as much basketball. Actually take my pre-season seriously."