(Reuters) – Roger Federer should play until he is 60 if he wants to, according to Romanian former world number one Ilie Nastase. Nastase the former bad boy of tennis, believes Federer should not listen to the naysayers, however. "I wish people wouldn't say that Roger Federer has to retire," the 67-year-old former French Open and U.S. Open champion was quoted as saying in Romanian media. "No, Federer doesn't have to prove anything, he can play to 60 if he wants to." Federer, who has spent a record 302 weeks as world number one during his illustrious career, is still one of the biggest draws in tennis, according to Nastase, even if he has fallen behind players such as Rafa Nadal and Novak Djokovic.