Reigning Olympic champion Rafael Nadal will miss the London Olympics after failing to recover from injury, the Spaniard said yesterday.

Nadal, who won the singles gold medal in Beijing four years ago, said he had failed to recover from a knee problem.

"I am not in a condition to be able to compete," the gold medal winner in Beijing said in a statement.

"It is one of the saddest moments of my career."

Nadal has not played since he was eliminated in the second round of Wimbledon to then 100th-ranked Lukas Rosol. He was set to be the flag bearer for Spain during the opening ceremony.