New Delhi: Top ranked Novak Djokovic, who is playing possibly the best tennis of his career, feels that Rafael Nadal still remains the major stumbling block in his bid to complete a career grand slam at the forthcoming French Open.
The Serbian, who crushed world No. 2 Andy Murray to win his sixth Australian Open and 11th Grand Slam on Sunday, said that Nadal 'absolutely' remains his greatest threat on clay-court, News.com.au reported.
The 28-year-old also added that Nadal is the king of clay, pointing towards the southpaw's record nine French Open titles.
Last season, Stan Wawrinka broke Djokovic's dream of completing a career Grand Slam as the Swiss crushed the Serb in the summit clash at Roland Garros.
With Nadal struggling to get his lost form back, Djokovic will start as the French Open favourite.