Former world number one Rafael Nadal has accused the ATP of not caring about professional tennis players.
The 11-time Grand Slam winner, who has only just returned from a seven-month spell on the sidelines with a knee injury, made the statement when asked about his opinion as to the number of games that the players are made to play on hard courts.
"The ATP worries too little about the players. It should care more for them," he said. "Hard courts are aggressive on the knees, back and ankles.
"To make a change like [reducing the amount of hard court events] it won't be possible in this generation but I think that the ATP has to work to think of how to lengthen tennis players' careers. Can you imagine football players playing on cement?"
Nadal is currently in Brazil where he will be competing at the Sao Paulo Open.