Athletic Bilbao defender Andoni Iraola will be sidelined for three weeks due to a muscle injury.
The 24-year-old injured his left leg last week and was unable to play in the 1-1 draw against Valencia on Saturday.
Iraola has now undergone more scans and club doctors have confirmed he will be out until early next month.
He is therefore likely to miss the upcoming games against Espanyol, Sevilla and Real Madrid.
Athletic have made a poor start to the season and are currently just one point above the relegation zone in La Liga.
Under-fire boss Felix Sarriugarte has already been hit by a series of injuries already and losing Iraola will be another massive blow.