McEnroe: Federer, Nadal won't win Australian Open

Federer and Nadal both cut their campaigns short last season as the former underwent knee surgery in February, while the latter was troubled by wrist issues.

Furthermore, McEnroe pointed out that he doesn’t expect the duo to be able to compete with world No 1 Andy Murray and Novak Djokovic, especially considering how dominant they have been in the last couple of years. 

"Let's hope they keep playing for 20 more years because they've been unbelievable for tennis," said McEnroe, as quoted by The Scotland Herald. "They're two of the all time greats, two of the all-time class acts in men's tennis.

"But I don't realistically expect either of them to be holding up the trophy at the end of this tournament. And I think probably if they took a truth test, they'd probably agree with that.

"But I don't expect either of them to be able to hold the trophy, particularly when you look at just the way Djokovic and Murray have looked in the last couple years, and have also started out the year.

"I'd really have to convince myself that they could pull something extraordinary to beat one or two of those guys in best-of-five sets, not to mention the rest of the field and the other players, the younger guys coming up like (Dominic) Thiem, (Alexander) Zverev, guys like that. I think it's going to be tough for them to do that."

McEnroe added that he is highly excited ahead of the Australian Open as Murray will be looking to continue his red-hot streak, while Djokovic will be on the hunt for his seventh Australian Open crown. 

However, should the Serb go on to win the first Grand Slam of the year, McEnroe insisted that it will be due to the fact that he has raised his game to the next level. 

"I'm always excited for the Australian Open because it's one of my favourite events," he said.

"I think there's a lot more buzz this year because Murray has taken over No 1, not by a long shot, but an amazing effort to do that. Djokovic is going to feel like he's got something to prove, even though he's had a couple of the greatest years ever in the history of men's tennis in the last couple years.

"Then you have Roger and Rafa coming back. You have still got the guys knocking on the door like (Kei) Nishikori. We haven't mentioned (Stan) Wawrinka, who has had an unbelievable couple of years."

As for Murray, McEnroe doesn’t expect him to succumb to the extra pressure that comes with being the top-ranked player in the world. 

"I think Andy will handle being No 1 just fine," he added. "He's been around long enough to know what it takes. He's worked extremely hard to get there... I certainly didn't think he could get there last year."