Rafael Nadal says the ATP is not doing enough to protect players' health, saying the increased number of tournaments on hard courts will lead to long-term injuries that will affect the players even after they retire.

Nadal says the ATP is not thinking of ways to lengthen the players' careers.

He says tennis is the only major sport where players are forced to play on cement and says it's an issue that doctors must get involved with, not only players.

Nadal is in Brazil to play his second tournament after a long layoff to recover from a left-knee injury. He lost in the final in Chile last week.

He says he is not worried about winning titles yet and his only focus is to regain rhythm on the court.