Fractured kneecap puts rest of Juan Martin del Potro's season in doubt

WATCH—Juan Martin Del Potro's injury scare in Shanghai:

Juan Martin del Potro's injury in Shanghai has been diagnosed as a kneecap fracture, and the world No. 4 is not sure if he will play again this season. The Argentine injured himself in a fall against Borna Coric, retiring following the first set.

"I made a weird movement with the knee and hit the floor very hard. I felt intense pain," Del Potro told the ATP, adding that he had attempted to keep playing at first but stopped when his knee kept giving him problems. "I didn’t want any more risks," he added.

An announcement from his representatives said that Del Potro experienced a "fracture of his right patella bone" and that "in the coming days, the doctors will evaluate the recovery process needed to return."

Del Potro recently reached the final of the US Open, his best showing since returning from several wrist surgeries, and was scheduled to play Basel and Paris, followed by his first showing at the ATP Tour Finals in London since 2013.

He called the diagnosis "a hard blow that leaves [him] without strength." He did not specify whether he will play again this season.

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