Barcelona midfielder Arturo Vidal reportedly stormed out of Tuesday's training session with the club after being informed that he would not be starting El Clasico.
The Spanish champions will welcome Real Madrid to Camp Nou on Wednesday night with both teams level on 35 points at the top of La Liga.
According to ESPN, upon learning that he would be starting on the bench against Zinedine Zidane's side, the Chile international refused to stay on after the main session for shooting practice.
Vidal, who has been linked with a January move to Inter Milan, has contributed four goals in 12 league appearances for the Spanish champions during the 2019-20 campaign.
The 32-year-old has not started a top-flight fixture since the start of November, though, and will reportedly not be in the XI that takes to the field on Wednesday evening.
Barca will finish their 2019 with a home game against Alaves on Saturday afternoon while Madrid will follow El Clasico with a clash against Athletic Bilbao at the Bernabeu on Sunday night.
Matt Law
