Argentine says Serb can overall Roger Federer"s total of 14 Grand Slam titles. US Open win was Djokovic"s second successive Slam success after his victory at Wimbledon. Juan Martin del Potro is certain Novak Djokovic has what it takes to become the greatest men’s player ever and beat Roger Federer’s current mark of 20 Grand Slam titles. Djokovic clinched his third US Open title on Sunday with a 6-3, 7-6, 6-3 triumph over Del Potro, taking him level with Pete Sampras’s mark of 14 Grand Slams. The 31-year-old Serb is now just three behind Rafael Nadal and six back from Federer, and Del Potro is convinced he has what it takes to end up with more Slam successes than both those all-time greats. “Of course he can,” the Argentine said when asked if Djokovic can claim the record over Federer. “He has 14 already. He won two Grand Slams in one year. He’s healthy. He has a great team working with him. “Hopefully him, Rafa, Roger will still fight for Grand Slams, because it is so nice to watch them fighting for the history. “We just do what we can against them. But Novak has everything to make records.” While not being drawn on whether he could end up with more Grand Slams than Federer and Nadal, Djokovic did credit the deadly duo for making him the player he is today. “Maybe 10 years ago I would say I’m not so happy to be part of this era with Nadal and Federer,” the 31-year-old said. “Today I really am. I feel like these guys, rivalries with these guys, matches with Federer and Nadal, have made me the player I am, have shaped me into the player I am today. “I owe it to them.”