French legend and former World No. 3 picks best player between Djokovic, Nadal and Federer

Novak Djokovic, Roger Federer and Rafael Nadal dominate the "greatest player of all time" debate in tennis. Here's what a French Open champion and former World No. 3 has to say about it.

• Former US No. 1 picks the greatest player between Roger Federer and Novak Djokovic
• Former World No.1 and four-time Grand Slam winner picks the best between Djokovic, Nadal and Federer