Rafael Nadal's expected absence from the end-of-season ATP World Tour Finals in London has been confirmed.
The 11-time Grand Slam winning Spaniard has not played since suffering a shock second-round defeat to Lukas Rosol at Wimbledon in June.
Since then, the 26-year-old from Mallorca has been struggling to overcome Hoffa syndrome, which is inflammation of the fatty tissue behind his left kneecap.
Not only will Nadal not compete at the O2 Arena next month, he also misses the Paris Masters and is expected to confirm he will be unavailable for the Davis Cup final in November.
He told reporters last month that he would not return to the professional circuit until he was 100 per cent fit.
Nadal was unable to defend his Olympic title during the summer, while Spain's Davis Cup final against the Czech Republic takes place in Prague from November 16-18.
He said in a statement: "It's disappointing to miss the last two tournaments of the season in Paris and London but it doesn't come as a surprise.
"I will hopefully resume my tennis practice soon since I am making good progress with my recovery from injury.
"I am not ready to compete in time for these events so I will continue my recovery in Mallorca."
Nadal has battled knee problems for years and his spot in the Tour Finals will go to the player ranked ninth in the standings, a position currently occupied by Serbian Janko Tipsarevic.