The six-times champion, who last played competitively at Wimbledon in July, says he is still managing the injury, which has caused him to abbreviate his service action. That's something really good from my side, especially from the knee. "I've just got to get through those matches and we'll see how far I can go".

Dimitrov's ranking brings me to another interesting observation. A Raonic-Del Potro-Djokovic/Zverev-Nadal run might be even steeper than the one he overcame previous year, but Federer too is even more in his zone than he was 12 months ago.

If fit and firing, 2009 champion Nadal will be hard to beat but needs to bring something new to the court if he ends up facing Federer, who won all four of their matches a year ago.

He retired during matches four times during 2017, including three in a row at Queen's Club, Wimbledon and at the ATP tournament in Washington.

The 36-year-old also has an outside shot of becoming the oldest World No.1 in history, but Nadal would have to lose before the quarter-finals for that to eventuate.

There's an extremely strong chance that Cilic will face worse players than himself until at least the quarter-final, and should Rafa get defeated, he would only face Pablo Carreno-Busta as a top ten opponent in the quarter.

Toni has departed to focus on his nephew's tennis academy but Nadal said their relationship remained intimate and "easy". And Nadal has plenty of previous when it comes to injuries.

"If I'm not feeling good, probably I will not be here", Nadal said after his error-filled loss to Richard Gasquet in an exhibition this week. I've had the luxury of getting treated in my room at my hotel. I don't know how it's going to behave. "I've played a lot of them now". At 22, I felt the same. I feel that I had a good week-and-ahalf of practices. "I'm just glad to be back playing tennis, having an opportunity to compete yet again in the big tournaments". Which should strike a chord of fear into the hearts of the tournament organisers.

He returns to the Australian Open, where he lost a thrilling five-set final to long-time rival Roger Federer in 2017, after overcoming his chronic knee problems just in time and hoping to continue last year's progress under new coach Carlos Moya. While he proclaimed last year's victory as being akin to a miracle, the bookmakers think very differently this year and have installed him as a firm 2-1 favourite to extend his collection of Grand Slam titles.

The Bulgarian came agonisingly close to beating Rafael Nadal in the semi-finals in Melbourne when he went down in a five-set humdinger, but finished the season ranked third after winning the biggest title of his career at the ATP Finals in London. Thiem isn't really the best hard court player while Zverev has yet to make it past the fourth round of a major.