Nadal & Federer out with injuries

Top seed Rafael Nadal and second seed Roger Federer pulled out of the Paris Masters with injuries on Friday.
Federer had been due to face James Blake in the quarter-finals but withdrew because of a back injury.
And Nadal pulled out with a knee injury when trailing Nikolay Davydenko 6-1, having earlier required treatment.
With defeats for Andy Murray on Friday and Novak Djokovic on Thursday, the tournament has now lost its top four seeds before the semi-finals.
Nadal had the trainer massaging his right thigh at the change of ends when trailing Davydenko 4-1 in the opening set, and called it quits two games later.
"This is the first time ever I've pulled out during a tournament, so it feels bad" Roger Federer"I had some pain in the knee yesterday," said the Spaniard. "I felt the pain a lot when I woke up this morning.
"When I push (on my right knee) I feel a sharp pain."
And Nadal admitted he is worried about whether he will be fit for the season-ending Masters Cup in Shanghai, which begins on 9 November.
"For sure," he said. "Hopefully it will be fine.... I don't know."
Federer has withdrawn during a tournament for the first time in his career.
"My back has been stiff for the last couple of days and I woke up this morning and it did not respond to the treatment I had last night," he told his website.