Top players led by world tennis number one Roger Federer have expressed their concern that Rafael Nadal will miss the US Open due to tendinitis in his left knee.
Federer says he was aware Nadal was unwell and it's disappointing for the sport that he won't be playing in New York and raises questions over whether he will be back on court this year.
Federer's sentiments were echoed by world No.2 Novak Djokovic and fourth-ranked Olympic gold medallist Andy Murray.
Nadal hasn't played since losing in the second round at Wimbledon almost two months ago.
The US Open begins on Monday week.