Upset that he was booed by a portion of the crowd after retiring against Rafael Nadal on Tuesday, Bernard Tomic says the reaction was “pretty unfair.”

The 21-year-old Australian called it quits after losing the first set, 6-4, and a scan Wednesday morning revealed that he has tear in his groin. If Tomic continued to play, doctors said he might have damaged it further and been out for up to four months.

"The form I was in, I was ready to challenge Rafa and unfortunately this happened," said Tomic. "I felt like I got booed a little bit on court, which was pretty unfair. I think I was misunderstood. Obviously they thought I was shaking Rafa's hand because he's too good and I'm forfeiting the match because I can't play against him. So I needed to say it was my leg. I don't think they quite understood that it was my leg."

Tomic, who reached the final of Sydney last week, said he was disappointed he had to stop because he felt like he was up to the challenge.

“I would love to play that match, because I had a lot to throw at him.” he said. “I was ready for the challenge. I was very confident. I knew I had the game to frustrate him and to get under him, but I just couldn't do it because I couldn't move and I was battling with pain. Lucky I stopped in the end, because I would have done myself a lot worse playing with Rafa another few hours on court. Who knows? Could have been another few months more, and then I would have dug myself a deeper hole. So I'm lucky I stopped.”

Tomic added that his priority is to get ready for Australia’s upcoming Davis Cup tie against France in two-and-a-half weeks' time. His doctor said the injury could take three weeks to heal.