Rafael Nadal admitted that he faces a "sea of doubt" about his chances of a successful return to tennis in August after missing two months with knee pain.
"I'm in a sea of doubt," said the world number two, who lost his top ranking after crashing out of the French Open in the fourth round and then sitting out with knee tendinitis during Wimbledon, which was won by Roger Federer.
Nadal had felt pain from the start of the European clay season and willed himself to play - and win - Monte Carlo, Barcelona and Rome over three consecutive weeks in April and May. "I didn't know when to stop," he said.
He said that playing in Madrid, where he lost the final to Federer after a marathon semifinal win over Novak Djokovic, was a step too far for his body.
"I came close to breaking," he said. "I wanted to play Madrid, but now I think it was a mistake."
The 23-year-old cleared the air about the recent separation of his parents, saying that the personal event did not affect his tennis.
"My family was always very supportive in my career," Nadal said.
"These changes are somewhat difficult to digest. But that's not what affected me. The real problem was my knees."
He said that returning to the game will be a gradual affair, perhaps with sharply redefined priorities."