The fifth-seeded Italian was dominating the 24-time Grand Slam winner 6-4, 6-3, 1-3 and well on his way to a maiden semi-final at Melbourne Park when he threw in the towel.

He had a medical timeout for treatment on his upper right leg and tried to continue, but his movement was badly impeded and he had to stop.

“I felt it at the beginning of the second set. I felt there was something strange in my right leg,” he said.

“I continued to play because I was playing really, really, really well, but I was feeling that the pain was increasing, and the problem was not going away.

“I feel personally that I know my body and I feel personally that I’m kind of secure that this is a tear, unfortunately.”

A torn muscle can take anything from weeks to months to recover from, depending on the severity.

Musetti had a similar injury when he was playing Carlos Alcaraz at the French Open last year.

He said this one was harder to take given he was on the cusp of making the last four.

“Honestly, I never imagined the feeling of leading two sets to zero against Novak and playing like that and having the lead of the match like that and being forced to retire,” he said.

“It is something that, of course, is really painful.”