"It should never be underestimated what Federer has done for the game, and he shows no sign of going away," Harman told CNN. "And I'm looking forward to Nadal returning at his best ."

The rivalry of the big four and their near total dominance of the slams has helped fuel the incredible global interest in tennis despite the economic downturn, with increased prize money, commercial revenues and crowds.

Despite Nadal's absence, record attendances are predicted at the Melbourne Tennis Center over the next fortnight as Djokovic and Murray bid to live up to Becker's prediction and Federer does his level best to prove him wrong.