Paris, May 26 -- Novak Djokovic on Monday IST revealed that Rafael Nadal's retirement has left a void in his career, making it difficult for him to find the same level of motivation he once had.

The Serbian great opened up about the emotional impact of his long-time rival's departure, even as Andy Murray praised the heartfelt tribute held for Nadal at Roland Garros.

"A part of me left with him and it's been a challenge to find my motivation again," Djokovic admitted on the sidelines of the French Open. "When Rafa stopped, I felt something I had never felt before. Honestly, I didn't think it would be like this. I thought, what do I do now?"

The comments came after a moving ceremony on Court Philippe-Chatrier where Djokovic, Murray and Ro...