Del Potro a major ATP Finals doubt due to fractured patella

Juan Martin del Potro said his latest injury blow is a "hard blow that leaves me without strength".

Juan Martin del Potro limps out of the Shanghai Masters

The luckless Juan Martin del Potro looks set to miss the ATP Finals after suffering a fracture to the patella of his right knee.

Del Potro retired as a result of a fall during his third-round match against Borna Coric at the Shanghai Masters this week.

The world number four looks unlikely to play in the season-ending showpiece in London next month after undergoing medical examinations on Saturday.

Jorge Viale, the Argentine's spokesperson, revealed the 30-year-old was fitted with a splint on his right leg and will be informed by doctors of a recovery process in the coming days.

"It's a very difficult moment. I feel very sad. It's a hard blow that leaves me without strength," said Del Potro, runner-up at the US Open last month.

"It's very difficult for me to think about recovery again, I did not expect this to happen."