World No.1 Rafael Nadal  has said that he still needs to improve his game as he prepares to launch his clay-court season in a bid to win his ninth French Open title.
The Spaniard, who has been hampered by a back injury which wrecked his Australian Open bid earlier this year, lost in straight sets in the final of the Miami Masters tournament on Sunday to second seeded Novak Djokovic 
According to Sport24, the 13-time Grand Slam winner said that despite the loss, which dropped him to 0-4 in Miami finals, he feels good about having made it to the final in Miami, although he believes that he needs to be 100 percent and work hard to be in better shape for clay.
The report mentioned that Miami is one of just three ATP Tour Masters 1000 events that Nadal, who has two titles in 2014 in Doha and Rio de Janeiro, has failed to win.
However, Nadal dismissed concerns over his back and quipped that he is still the 'King of Clay', a nickname he earned due to his success on clay courts.
By winning last year's French Open, Nadal became the first player to win a single Grand Slam tournament eight times, the report added. (ANI )