(CNN) -- Rafael Nadal is determined to put the most "difficult moments" of his tennis career firmly behind him by regaining his French Open title from arch-rival Roger Federer.
Nadal crashed to a four-set defeat to Swede Robin Soderling in the last 16 at Roland Garros last year to leave the way clear for the Swiss maestro to complete a career grand slam on all four surfaces.
Spain's Nadal had gone into the second slam of the year with the Australian Open under his belt and firmly ensconced as world number one.
He left it with his unbeaten record at Roland Garros in tatters after a defeat that Federer told CNN was totally unexpected.
"I went back to hotel at the end of my match and watched it on television and at the end of it I said 'Oh my God' I can't believe Rafa lost a match at the French Open."
But it proved only the beginning of Nadal's troubles as injuries proceeded to wreck his 2009 campaign and left him unable to defend his hard-won Wimbledon crown.
"It was a difficult moment for me after losing at Roland Garros. At the same time I had a little personal problem (his parents divorced) and also problems with my knees, too many things," he told CNN's Open Court.
Nadal took consolation in taking a complete break from the game to recuperate from his injuries in his native Majorca, "it's the best place to be in summer" before embarking on the autumn hard court swing in the U.S.
With his aura of invincibility fading and lacking match practice, results were mixed but he did reach the semifinals of the U.S. Open before losing to eventual winner Juan Martin Del Potro.
The start of 2010 showed more promise until he struggled to a quarterfinal defeat to Andy Murray at the Australian Open, clearly hindered again by his knee problem.
But returning this spring to his favored clay, Nadal once again looks all-conquering with wins at the Masters 1000 tournaments in Monte Carlo and Rome.
It surely points to a fifth title triumph in the French Open and Nadal admits that represents his best chance of winning a grand slam this year.
"Roland Garros for sure is the most important tournament in my career, to win four times there and it's on clay, for the Spanish that's special."
Nadal was inspired as a youngster by fellow Majorcan Carlos Moya who won the French Open in 1998, backing up the double success for Spain's Sergi Bruguera in 1993 and 1994.
Bruguera, who now runs a tennis academy, has no doubts his predecessor can claim the title again. "I'm 100 per cent certain he will win," he told CNN.
One of Nadal's main rivals, his compatriot David Ferrer, knows the task facing the challengers.
"I think he's favorite, he's the greatest clay court player in history," was the verdict of the world number 12.
Even Federer is in awe of Nadal's unique talents on the red stuff, telling CNN "it's like playing someone with two forehands."
"It's nice of Roger to say that," said the unassuming and rather shy Nadal, who transforms into a ruthless terminator once the action begins on a tennis court.