At a press conference in Argentina promoting an upcoming exhibition match, Roger Federer says that 2009 U.S. Open champion Juan Martin del Potro can reach the top rung of the game.



“He is already among the best, now he just has to train hard and stay on the same path,” Federer said. “He was No. 4, he’s now 7, but he could be No. 1. Sometimes the difference is in the small details.”



Federer also told La Nation that in 20 years, he may still be involved in tennis and that he “could be a coach, but I do not know. I’ll see what the situation with my daughters and my wife is. I still like to travel, but also enjoy being at home. I’m so happy.”