The finale to the tennis season has been further rocked by the possible absence of world number one Rafael Nadal.
The Spaniard's participation at the ATP Finals in London on November 12th is up in the air after this year's French and US Open winner pulled out of his quarter-final at the Paris Masters last week due to a long-standing knee-injury.
Season-ending injuries have already meant Andy Murray, Nadal Djokovic and Stan Wawrinka will be missing from the O2 event, leaving just Nadal and Roger Federer still standing from the elite’s old guard.
Apologising to fans in Paris, Nadal, 31, threw doubt on whether he would play again this year when he said: "I'm not thinking about London, I'm thinking long term, to be able to continue playing tennis."
Sky Sports commentator Mark Petchey for one does not think Nadal will risk aggravating the injury further.
Petchey said: "Nadal said in his press conference there's no chance of him playing three matches.
"I think he'll be very, very doubtful for London, to be honest.
"If I was betting, I'd bet he wouldn't play right now.
"He wants to get out there but he's got to think about his career. He's got to think about the next three or four years.
"He can't think about London as just a solo event.
"Obviously it's one of the major ones he hasn't won but he's got to play three matches as it's a round robin.
"He will be thinking of Australia as he's thinking about that decision.
"He will want to get out there, he's a competitor, he's a champion and he wants to grace every major court around the world and have his presence there.
"But he's still got to be smart about the long-term impact on his career."
And with Federer unable to catch him at the top of the world rankings, it appears a risk not worth taking.
However, Doctor Angel Ruiz Cotorro still had some words of optimism for fans hoping to see a renewal of one of the greatest rivalries in tennis.
Scans have shown no new damage and Cottoro told Spanish newspaper El Espanol:
"The first thing was to stop and assess how the knee was, if something new had happened.
Now we know that there is nothing different, which is a situation that had been dragging on for some time.
The problem of tendons in different situations may bother more or less, but we will try to be good to play in London.
A last-minute decision looks likely with Cottoro adding: "If he is well, he will play, and if he is not well, he will give up playing. You have to see how it evolves these days."
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