Madrid - Spanish flag-bearer Rafael Nadal has confessed that his chronic knee problems could still plague him when the London Olympic tennis event begins in less than a fortnight.
The tennis world No 3, who has rested and taken treatment since crashing out in the Wimbledon second round three weeks ago, said that he can only hope for the best after returning to the practise court following a holiday.
"I'm doing everything to recover," said the 11-time Grand Slam winner, who claimed a record seventh Roland Garros clay title last month shortly before rival and No 1 Roger Federer won his seventh at Wimbledon.
"My excitement is building and I'm working as hard as I can in hope of being 100 per cent."
The 26-year-old characterised himself as "the one who is most worried."
"I hope things improve, I want to arrive in London well-prepared and recuperated."
Nadal won gold in Beijing four years ago. His current injury problems forced him to cancel an exhibition with Novak Djokovic set for last weekend in Madrid at the Santiago Bernabeu stadium.