The uncle and former coach of Rafael Nadal has revealed that the tennis great "continuously lives with pain" and makes regular use of painkillers.
Toni Nadal, who stepped down as his nephew's coach by the end of last season, added that the current world number two would rather have won less money and trophies during his career in exchange for less pain.
"Since 2005 my nephew continuously lives with pain and then subsequent soothing with painkillers," Toni explained at a Management and Sport conference at the Murcia School of Sport and Business.
"It has got to the point where we are looking at his health ahead of matches.
"Many times he's told me that he would have liked to earn less money in exchange for suffering less pain."
Nadal has won 16 Grand Slam singles titles, 30 ATP World Tour Masters 1000 titles, 19 ATP World Tour 500 tournaments, and the 2008 Olympic gold medal in singles.