Roger Federer
Ilie Nastase (L) not ready to label Roger Federer the greatest of all time Getty

Former world number one Ilie Nastase has reserved judgment when it comes to labelling Roger Federer as the greatest tennis player of all time and is keen that 'we' wait before making such a claim.

The 70-year-old Romanian believes conclusions on the best ever in any sport are reached far too easily and it is often the contemporary stars, who have been at the peak of their respective disciplines over a period of time.

Federer has established himself as one of the greatest to play the game after capturing his 18th Grand Slam title – four more than second-placed Pete Sampras and Rafael Nadal – but the two-time Grand Slam champion feels that it is not fair to compare players from different eras, citing the example of Rod Laver, who has completed the calendar Grand Slam on two occasions, something the Swiss ace has failed to do.

"We have to wait to see if Roger Federer is the greatest of all time, I don't want to compare because it's not fair for other players before like Rod Laver, Pete Sampras," he told Omnisport, as quoted by tennisworldusa.org.

The former French Open winner also referred to other sports where the current stars are hailed as the best ever. In Formula One, Aryton Senna is widely regarded as the best driver of all time, but the Brazilian managed just three world championships before his passing in an accident, and there are a number of drivers who have won more titles, while showing similar levels of skill in the car.

"Now people just look at the players at the top now. All sports are the same. Maybe after Lionel Messi and Cristiano Ronaldo, there will be other guys in 10 years," the Romanian said, referring to the two best football players in the world at the moment."I do not want to compare because all of them are great champions and all played at their best."

The Tennis Hall of Famer also spoke about Novak Djokovic and has backed the Serb to return to form after a recent run of poor results. The world number two was knocked out in the second round of the Australian Open, and lost again in the quarter-finals at the Mexico Telcel Open after which he revealed that tennis was not his number one priority at the moment.

"I think he's going to be back. He can't just play from Monday to Sunday and start fresh on Monday like others. People don't understand that. There's just pressure for him to win week by week and you get tired and you cannot concentrate for so long," he explained.

"Maybe the other guys play well, that's also possible. But Djokovic is a great champion and you have to count on him coming back, that's for sure. He's a fighter."