MONTE CARLO, April 21 Rafael Nadal admitted he is still trying to recapture his best form but remained optimistic for the French Open after losing his Monte Carlo crown to Novak Djokovic on Sunday.
Nadal, who returned to action in March after seven months out with injury, went down 6-2 7-6 to the Serbian world number one, ending his eight-year reign on the principality's clay.
"I need to put in a little bit more physical performance," the Spaniard told a news conference.
"That's the real thing - to play all the points with the same intensity. I get tired to play with that intensity, earlier than what I used to."
Nadal had won three tournaments, including the Indian Wells Masters, and reached the final in Vina del Mar since returning from the serious knee injury that kept him out for the second half of last season.
And although he had said this week he wanted to concentrate on his tennis rather than his fitness, he added: "I think I'm in the right way.
"Five finals in a row. If you had told me that four months before, I would have cried for emotions, no? I'm very happy to be able to play against the best players of the world and play with real chances.
"I think for me it was a positive week...I didn't practise in Mallorca (his home base). I just practised here before the tournament. With not much preparation, I was able to play in the finals."
The French Open begins on May 26, when Nadal will be aiming to win his eighth Roland Garros championship.
"This week is going to help me be fit for the next weeks," he said. "Hopefully I can play another great week in Barcelona next week, play some matches that will keep helping to put me in 100 per cent (shape) physically.
"Roland Garros is very far. I needed more matches to play with this intensity all the time. The competition gives you these special things, extra things that you may need sometimes when you are playing against some players.
"We have Barcelona, then we have Madrid, then we have Rome. It's enough time, I think. Yes. It's more than enough."
(Editing by Stephen Wood)