I am not invincible on clay, says Nadal

Spaniard keen on improving his game

The world number one beat fellow Spaniard David Ferrer 6-4, 7-5 in Sunday's final but explained he was still a little rusty on clay, his favourite surface.  "I'm pleased with how the first week (on clay) has gone," Nadal told a news conference at the Barcelona Open on Monday.  "I need to use the confidence from the first week to keep improving. I have to be more aggressive, to serve better and to finish off points more emphatically and with more authority."

After Barcelona, Nadal will compete in Madrid, Rome and then at the French Open in Paris, giving him three possible chances of a clash with in-form Serb Novak Djokovic.

The world number two has won 24 successive matches in 2011, including final victories over Nadal at Indian Wells and Miami, and a claycourt showdown between the two is eagerly anticipated.

It was put to Nadal that Djokovic rather than Roger Federer was now his main rival for the number one spot.

"He (Djokovic) has started very well and I congratulate him," said the five-times French Open champion.

"Roger and I have played many important matches, with great moments for each of us. The year is very long and he (Djokovic) is in a privileged position but unfortunately I have to worry about many others as well.

"I'm not invincible on clay. I have lost before and unfortunately I have plenty more games I will lose in the future. It has gone well for me in recent years but no one is perfect."

Nadal’s team-mate David Ferrer, who he beat at Monte Carlo, was all praise for the World No 1. Nadal is also only 24 and has amassed a record 19 Masters titles.

His dominance on clay has put him on course to win every claycourt event he enters this year just like in 2010. "Rafa is incredible on clay, he is everywhere at the same time," fellow Spaniard Ferrer told reporters. "Maybe if Rafa is injured I have a chance (next year)."

With Nadal's French Open defence on the horizon after he plays at Barcelona, Madrid and Rome, world number two Djokovic will have to quickly get over the minor knee injury which ruled him out this week and find a way to hurt the Spaniard on clay.

Nadal's own struggle with injuries is one obvious way in which he can be toppled but he denied playing the non-mandatory Barcelona tournament next week could be too big a risk.