Real Madrid striker Karim Benzema is set for a spell on the sidelines of up to three weeks after suffering a hip injury, Marca have reported.
The news will come as a setback for Los Blancos coach Zinedine Zidane, who will be short of attacking options for his side's upcoming fixtures.
Benzema will miss the Copa del Rey double-header with Numancia, a La Liga clash with Celta Vigo, and potentially the games against Villarreal and Deportivo La Coruna.
The Frenchman is believed to have picked up the problem early in last weekend's Clasico defeat, before being replaced in the second-half following Dani Carvajal's sending off.
But AS claim that Benzema showed "no sign of discomfort during the game", and was not injured against Barcelona.
The 30-year-old was reportedly seen in "perfect health" as Real Madrid's players departed for a winter break in Dubai last week.
Benzema's injury came as Los Blancos made a return to training ahead of their return to competitive football next month.
Some have suggested that he was simply attempting to avoid training in front of the club's fans, many of whom have expressed their distaste over Benzema's form in recent weeks.
But confirmation from Real Madrid's website debunks such claims, leaving Zidane with a dilemma as to who to select as his attacking focal point in the coming weeks.
Los Blancos currently sit in fourth place in La Liga, 14 points behind leaders Barcelona after their 3-0 defeat at the Bernabeu.