Rafael Nadal's uncle and coach told Television Española Thursday that the Spanish tennis great is focused on making "a full recovery" from a nagging knee injury after withdrawing from the U.S. Open.

"After Wimbledon, we decided to rest a few days and then move on to strengthening the quadriceps but that's was a struggle," Toni Nadal said in explaining his nephew's decision to withdraw in succession from the London Olympics and then from two ATP World Tour Masters 1000 events in Toronto and Cincinnati.

"Later we managed to strengthen a bit, but at the end of the training sessions that pain continued and the recovery was not sufficient to deal with a competition as tough as the U.S. Open and the rest of the season," the coach said in the phone interview with TVE, alluding to that Grand Slam event's unforgiving hard-court surface.

"Now we're training normally but it's not the same as competing for four hours in a tournament," he said, adding that he is confident his nephew will be ready to play in the Davis Cup semifinals from Sept. 14-16, when Spain hosts the United States on a clay court in the northwestern city of Gijon.

"There's a month to go and we hope he's fine, if not technically then at least physically," the coach said.

Nadal began the summer on a high note by capturing a record seventh French Open title with a victory over then-world No. 1 Novak Djokovic of Serbia in the final.

But the 26-year-old Spaniard was stunned two weeks later in the second round of Wimbledon by unheralded Czech Lukas Rosol, a defeat regarded as one of the biggest upsets in that prestigious tournament's long history.

The 11-time Grand Slam champion has struggled to stay healthy during his career, having been forced to withdraw from each of the four Grand Slam events due to various injuries. EFE