Novak Djokovic said on Friday that he was “overwhelmed” by the news of Rafael Nadal’s retirement and called the Spaniard “the greatest rival that I ever had,” but insisted that he has no plans to stop. 

Nadal announced Thursday that he will step back from tennis after the Davis Cup finals in November, ending his 22 Grand Slam-winning career. He clashed 60 times with Djokovic, who edged their rivalry 31-29.