Defending champion out of Olympics

Spain's chances of securing gold in the men's tennis at the Olympics has taken a blow after the withdrawal of Rafael Nadal.

One of the superstars of world tennis over the last few years has pulled out because of injury, saying he is not fit enough to take his place among the elite.
Nadal suffered a surprise second-round defeat at Wimbledon earlier this summer after going down to world number 100 Lukas Rosol.
The shock exit came hot on the heels of the defending Olympic champion, 26, winning the French Open after beating Novak Djokovic in the Roland Garros final.
Nadal has a history of knee trouble but has still been able to claim 11 Grand Slam titles since his breakthrough in 2005.