Athletic Bilbao boss Marco Bielsa and Spanish striker Fernando Llorente reportedly had a training ground row on Monday.
Llorente is expected to depart Bilbao in January after confirming that he will not sign a new deal with the club in the summer.
Bielsa has used the striker sparingly this season following the news and according to Goal.com, the pair clashed in training with the 27-year-old being sent to the changing rooms.
Llorente has scored one goal for the club this season.