- ATP Tour
Federer predicts Del Potro will follow in his footsteps
Federer was beaten 3-6 6-3 6-4 by Del Potro in the first of two exhibition matches during his tour of South America.
The world No. 2, who is visiting Brazil, Argentina and Colombia, boasts a 13-4 record against Del Potro, but the Argentine has won their last two, (not counting Wednesday's exhibition match) - beating Federer in the Basel final before a victory at the ATP World Tour Finals.
His first win against Federer came in the 2009 US Open final, where he stunned the world No. 1 3-6 7-6(5) 4-6 7-6(4), 6-2 to win his first, and to date only, grand slam title.
But having only recently returned to his best after a nasty wrist injury that saw him miss most of the 2010 season, Del Potro is back in the world's top ten, and Federer believes the 24-year-old is on an upward curve.
"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."