Nadal pulls out of semifinal with knee injury

Rafa Nadal has been forced to pull out of his semi-final against Andy Murray at the Sony Ericsson Open due to a knee injury, the world number two said on Friday.

Nadal, who has had problems with his knees before on the American hardcourts, apologized for withdrawing from the Masters series event, but said he had to.

“I am not ready to compete today. I am very sorry for the fans. I’m very sorry for the tournament. I’m very sorry for everybody who were ready to watch the match on the television,” Nadal told a news conference.

“I take no pleasure from this but I cannot do anything else. I am not ready to compete, and I cannot go on court and lie to everybody.”

Murray, the Miami champion in 2009, was gifted his second walkover of the tournament and place in Sunday’s final.

The Scotsman will play the winner of the other semi-final, between top-seeded Serb Novak Djokovic and Juan Monaco of Argentina, which was due to take place later on Friday.

Nadal, who has suffered from tendinitis in his knees several times during his career, had dropped only one set on his way to the last four as he chased a first title since last year’s French Open.

He suggested the injury was probably a recurrence of his previous knee troubles.

“I have to see a doctor but it looks like nothing really, different than what happened a few times in the past,” he said.

The 25-year-old Spaniard, runner-up in Miami three times, has won 13 of his 18 meetings with Murray, although all five of the Scot’s victories came on hard courts.

In 2009, Nadal pulled out of Wimbledon, where he had won the year before, because of knee problems.

At the 2010 Australian Open, where he was the defending champion, he retired from his quarter-final clash with Murray, again because of knee problems.