The 29-year-old has suffered pains in his knee over tha past eight months owing to calcification of the tibia and surgical scarring on his left knee.

Runco said that the striker, who scored three times at the World Cup to become the all-time tournament leading scorer despite Brazil's exit to France in the quarter-finals, had complained of pain at times during the event.

"He said now the event was over he would use the break to have surgery as he's had to put up with it for eight months," Runco said.

"If it is what I think it is, it will involve swift surgery and he will be ready for the new season," said Runco, who added Ronaldo would also consult Real's medical staff.