Rafael Nadal's doctor takes stock of his injury after successful surgery | Tennis | sport

Nadal has not played on a tennis court since his retirement in the semifinals of the US Open against Juan Martin del Potro.

The Spaniard suffered a knee injury for seven weeks, but had to return to the Paris Masters last week until he had a stomach problem.

The world No. 2 took the last minute decision to retire from the finals of the ATP circuit in order to make sure it is fit for next year.

Nadal went under the knife on Monday and the procedure went as planned.

"Rafa Nadal underwent arthroscopic surgery on his right ankle to remove a free body," said Dr. Angel Ruiz-Cotorro.

"The intervention of doctors Vilaro and Ruiz-Cotorro was normal."

Nadal had issued a statement earlier in the day announcing that his season was premature.

"It was a complicated year, very good at tennis when I was able to play and at the same time very bad when it came to injuries," he said.

"I did everything to reach the end of the season in good condition, in Paris and London, doing things right and I really wanted to play.

"Unfortunately, I had an abdominal problem in Paris last week and, in addition, I have a free ankle body that needs to be removed in the operating room today.

"It is true that we had detected it for a long time and that it bothered me from time to time.

"However, as the problem of abdominal muscles prevents me from playing in London, we are taking advantage of this moment to remove the free body and avoid future problems.

"In this way, I hope to be in great shape for the next season. Thank you all for the support. "

Nadal's withdrawal from the ATP Tour final means that John Isner participated in the contest.

Roger Federer, Kevin Anderson, Dominic Thiem and Kei Nishikori were drawn in the same group.

Novak Djokovic was paired with Alexander Zverev, Marin Cilic and Isner.