Former World No. 1 and seven-time Grand Slam champion chooses best tennis player of all time

Novak Djokovic, Roger Federer, and Rafael Nadal have dominated the 'Greatest of All Time' debate in tennis in recent years. Here's what a former World No. 1 and seven-time Grand Slam champion has to say about it.

• Novak Djokovic reveals details from his relationship with Nadal and Federer: ‘I didn't receive acceptance’
• Serena Williams chooses between Federer, Nadal, and Djokovic as the greatest male tennis player