Rafael Nadal withdraws from London Olympics

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

Nadal, who won the singles gold medal in Beijing four years ago, said he had not recovered from a knee problem.

"I am not in a condition to be able to compete," the Beijing gold medal winner said in a statement. "It is one of the saddest moments of my career."

Nadal - ranked third in the world - has not played since his shocking second-round Wimbledon loss to then-No. 100 Lukas Rosol.

No athlete has ever won back-to-back gold medals in Olympic tennis singles, a streak that is sure to continue thanks to Nadal's absence.