Eden Hazard failed to appear at Real Madrid training on Monday.
The Belgium international is now an injury doubt for the second-leg of their Champions League round 16 tie with Atalanta.
Hazard featured in the win against Elche, but wasn't on the Valdebebas training pitch on Monday.
Real coach Zinedine Zidane asked for "patience" after the Belgian's return against Elche, but management had pinned many of its hopes on having one of its best players available for their clash with the Oribici.
Zidane is due to discuss Hazard's situation later today.