Nadal still unsure if he will be fit for the ATP Finals
The world number one is struggling to overcome a knee problem ahead of his scheduled opening match on Monday against David Goffin.
Rafael Nadal has said that despite some improvement on the knee problem that forced him to pull out of the Paris Masters he still cannot guarantee he will be fit to play at the ATP Finals in Londond.
Nadal is due to play Belgium's David Goffin in his first match at the tournament on Monday, but told reporters that his injured knee might not hold up.
"I'm doing my best," said the Spaniard, twice a runner-up but never champion of the season-ending event. "I hope... [but] if I am not ready by Monday I won't be here. If something negative happens, that's it and you go home. "[But] my plan is to play here and be competing well."
Nadal withdrew from the final Masters tournament of the season in Paris ahead of the quarterfinals when his knee flared up but London tournament organisers, as well as fans with tickets, will be praying the world's top tennis player will be healthy enough to feature.
Federer: "He's a superstar... we hope he plays well"
World number two Roger Federer said it would be a blow for Nadal to miss out.
"He's a superstar of our game. If he's here, that's a very good sign. It will be interesting but we hope he plays well," said the Swiss.
Nadal practised on centre court at the O2 Arena on Friday, hitting with Croatian Marin Cilic, who is also among the top eight ranked players competing. He shared jokes with coaches Carlos Moyá and Toni Nadal on the court, but appeared frustrated at other moments with an injury that is clearly aggravating him.