Roger Federer and Rafael Nadal's 'biggest challenge' earmarked by former pro

Tim Henman has lauded Rafael Nadal and Roger Federer as the greatest ever players to grace the tennis court and their achievements in 2017 should not come as a surprise to anyone. However, the biggest challenge for them going into the new season would be to make sure that they stay healthy, the former tennis player said.

Federer has won seven titles this year, including the Australian Open and a record eighth Wimbledon title to overtake Pete Sampras' seven championship wins.

The 19-time men's singles Grand Slam winner came back from a six-month break in 2016 in spectacular fashion, when he won the Australian Open in January, the first grand slam he went on to win in over four years. After missing the French Open owing to injury problems, he fought back and went on to win the Wimbledon title, proving that he was still among the greats to rule the court.

Nadal more than matched his conquests, winning six titles in the year, including the French Open and the US Open. The Spaniard, however, had the last laugh as he finished the year with the number one rank, sealing the spot after progressing into the quarter-finals of the Paris Masters.

Henman believes that both go in as favourites for the Australian Open should they be 100% fit and no one should be surprised by their achievements as they are among the best sportsmen in all sports combined.

"Phenomenal. I think if you are surprised by Federer and Nadal, I think you are naive. Because now they are two of the greatest athletes in any sport of all time. They don't go by normal rules," Henman told Express Sport.

"I think what Federer and Nadal achieved this year was absolutely incredible and I would not be the slightest bit surprised if they did it all again next year. That's how good they are. The biggest challenge for both them is making sure they stay healthy.

"As we all know, that gets harder and harder as you get older. But the way they played this year, head and shoulders above the rest as number one and two in the world. And they go into the Australian Open as the favourites if they are 100 per cent healthy."