Marcelo Zalayeta went under the knife on Monday to repair his cruciate ligament damage.
The Napoli striker suffered the injury against title-chasing Roma last weekend and is now facing a prolonged spell on the sidelines.
He is expected to be out of action for up to six months, ruling him out of Edoardo Reja's plans for the remainder of the season.
The unfortunate Zalayeta had been enjoying a successful first season in Naples following his summer switch from Juventus, finding the net eight times in his 22 Serie A appearances.
The good news for Napoli though is that the operation is thought to have been a complete success and the Uruguayan is expected to make a full recovery.
However, the club are in no rush for him to begin his rehabilitation any time soon, as cruciate ligament injuries are prone to relapses if pushed too hard, too soon.