Rafa Nadal has said was struggling with nerves and self-confidence issues after he was beaten in the third round by fellow Spaniard Fernando Verdasco at the Miami Open on Sunday.
"It is not a question of tennis. The thing is the question of being relaxed enough to play well on court," he told reporters after the 6-4 2-6 6-3 loss at Key Biscayne.
"A month and a half ago I didn't have the game. My game has improved but …I am still playing with too much nerves for a lot of moments, important moments, still a little anxious on those moments," he added.
Nadal rejected the notion his numerous past injury problems were leading him to doubt his body.
"The physical problems are in the past. I am in competition. I'm playing weeks in a row. Is not an excuse," he said.
"It is a different story today.
"I am feeling more tired than usual, feeling that I don't have this self confidence that when I hit the ball I am going to hit the ball where I want to hit the ball, to go for the ball knowing that my position will be the right one.
"All these are small things that are difficult to explain.
"One of the tougher things has been fixed, that is the game, in my opinion. Now I need to fix again the nerves, the self-control on court. That's another issue.
"I am a little bit on and off too much. That is something that didn't happen in the past.
"In the past I have been able to change a lot of situations, negative situations, in my career and I want to do it again.
"I am confident that I can do it. I don't know if I am going to do it but I hope I can," he said.
With the clay court part of the season coming up, Nadal's preferred surface, he said the opportunity is there for him to turn his form around but he said that would not happen if he is unable to fix his mental issues.
"The tournaments that are coming are historically good for my game, good tournaments for my confidence," he said.
"But if I'm not able to control all these things, I am not going to have the possibility to compete well and have success in those events."