"The operation went well. The intervention was of the same type as the one in 2000. The healing period should now last nine months," Dr. Gerard Saillant told l'Equipe.

El Fenomeno had a two-hour operation on Thursday evening to repair a ruptured tendon in his left knee and now he needs about 10 days of physical therapy.

The 31-year old marksman is seriously in doubt with the Rossoneri as he has only featured in five games this season and struggled since last summer with a series of injuries.

His contract expires at the end of the season and the Milan bosses are still silent on the issue.

Ronaldo was injured in last Wednesday 1-1 draw with Livorno. He had to travel to Paris on Thursday to undergo the hospital.