Federer or Djokovic? Rafael Nadal compares his top two rivals, labels the Serbian 'invincible'

Rafael Nadal is convinced that Roger Federer is the best in the history of the sport owing to his accomplishments in terms of major titles, but believes on a technical level Novak Djokovic is at a higher level.

The Spaniard was discussing the best player he had ever come up against and it was between the Swiss ace and the Serbian, who have been his main rivals over the last decade.

The trio has won 43 of the last 51 Grand Slam titles following Marat Safin's win at the Australian Open in 2005. They have dominated the men's game and are clearly at another level compared to any other player in the current era.

Nadal remained non-committal when asked to name one player but admitted that it could be Federer owing to his achievements. However, the Spaniard has a much better head-to-head record against the 19-time men's singles Grand Slam champion as he has won 23 of their 38 clashes.

Against Djokovic, on the other hand, the Spaniard does not have the upper hand as the Serb holds a slender 26-24 advantage. However, the latter has won seven of their last eight meetings, which was during his period of dominance.

"Well, it's complicated. What with titles and what he's accomplished that says he's [Federer] the best in the history of our sport," Nadal told Spanish radio station Cadena Ser, as quoted by the Metro.

"Is he the best I've played against? Well, maybe, yes, I've also played the great Djokovic, we've run into other really good players.

"But it'd be unfair to say that Federer isn't the best I've ever played against because the titles and his track record prove that to be the case. But at a technical level, when Djokovic has been at the top of his game, I have to say that I've been up against an invincible player," the 16-time major winner added.

Nadal and Federer had phenomenal 2017 campaigns winning a combined 13 titles which include equally sharing the four Grand Slams between them. They also ended the year as the top two ranked players in the ATP ranking respectively.

Djokovic, on the other hand, will start the year as the world number 12 after he ended his season following his loss in the quarter-finals at Wimbledon. He is currently on his way back from an elbow injury and will return to the court at the Qatar Open in January.