It was confirmed on Thursday that Real Madrids striker Ronaldo will undergo a surgery on his left tibia at 10:30 am on Saturday in Rio de Janeiro.

Brazil's soccer striker Ronaldo listens to questions during a news conference in Rio de Janeiro July 11, 2006.[Reuters]

Brazilian national team physician Jose Luis Runco will perform the surgery and Real Madrid medical director Alfonso del Corral will follow the operation.

On July 5, Runco said that Ronaldo had been suffering from pains in the knee for eight months due to two calcifications in his tibia and that the player would probably take advantage of the break after the World Cup to undergo the surgery.

The physician also said then that the injury may have been caused by trauma or by work overload.

The confirmation of the surgery contradicts declarations of Real Madrids executives two weeks ago, saying that the striker only needed to rest to recover from the pains.

The surgery consists of a scaling in the affected area. After the procedure, a press conference with the physicians will be held at the Pasteur Hospitals auditorium to give further details about the operation and the subsequent rehabilitation treatment.

Ronaldo is expected to be back to the pitch in August, when Real Madrid will play against the Real Salt-Lake in the United States as a preparation for the 2006/2007 Spanish and European leagues.