Valencia striker Alvaro Negredo has undergone emergency surgery for acute appendicitis.
The Liga club confirmed in a statement that the Spain striker was rushed to hospital and went under the knife.
No comment was made on how long Negredo was expected to be out for, but reports suggest he will be sidelined for at least a month.
It has been a frustrating season for the former Manchester City striker, who has not featured for Valencia since a 3-1 defeat against Athletic Bilbao on October 3.
Negredo criticised head coach Nuno Espirito Santo in an interview following a slow start to the season, although talk of a rift was played down.
Nuno insisted earlier this month that Negredo's absence from the first team was owing to performance-related issues.