(Reuters) - Former Wimbledon finalist David Nalbandian said the younger players on the men’s ATP Tour must start believing in themselves if they are to close the gap on Roger Federer, Rafa Nadal and Novak Djokovic. Russian Daniil Medvedev looked closest to ending the Grand Slam hegemony of the ‘Big Three’ when he cantered into the Australian Open final on a 20-match winning streak that included 12 straight wins over top-10 opponents. But that run counted for nothing as Djokovic won in straight sets for a record-extending ninth triumph at Melbourne Park, the Serb’s 18th Grand Slam trophy. Nalbandian told the ATP’s website that Medvedev’s march to victory at the ATP Finals in November, during which he defeated both Djokovic and Nadal, showed the rest of the tour anything is possible. “That showed that everybody can beat them,” said the former world number three. “They’re incredible players, but they’re not superheroes. The new generation has to start believing in themselves.” Djokovic’s triumph in Melbourne meant 15 of the last 16 majors have been won by the Big Three. Austrian Dominic Thiem won his maiden Grand Slam at last year’s U.S. Open but Nadal and Federer had skipped the trip to New York while Djokovic exited in the fourth round after he was defaulted for accidentally striking a line judge with a ball. Argentine Nalbandian, the 2002 Wimbledon runner-up, defeated Nadal, Djokovic and Federer in consecutive matches to win the Madrid Masters in 2007. “Most of the players think that they’re waiting for the Big Three to retire,” said Nalbandian, who recently took a part-time coaching gig with Serbian world number 41 Miomir Kecmanovic. “I say, ‘I was already waiting in my time and they’re still around!’ Let’s stop waiting and beat them. “It’s incredible the way that they adapt to the new players and their age, because they’re getting older. They’re still on, they’re still focused, they’re still inspired to keep going. “That’s amazing. That’s why there are only three players who can do that. The others can’t do that. Nobody.”