Athletic Bilbao striker Fernando Llorente is reportedly in danger of missing Thursday's Europa League contest against Manchester United.
Llorente, 27, missed Tuesday's training session with a series of minor fitness problems and it is understood that he may not be available, according to AS.
He scored his side's first goal during their 3-2 victory over United last week, in an impressive performance from the powerful forward.
The Spaniard has 21 goals in all competitions for Bilbao this season.