Spain international striker Diego Costa refused to take part in training on Thursday after learning that Atlético Madrid had opened internal disciplinary hearings following his red card against Barcelona.
The 30-year-old was handed an eight-match ban the footballing authorities after he launched a foul-mouthed rant at referee Jesús Gil Manzano.
The club have also decided to explore options to punish Costa even further, and AS claim that the striker refused to train with his teammates after learning of Atlético Madrid's intentions to take matters further.
Atlético have already confirmed that Costa isn't struggling with an injury.
Costa's early red card against Barcelona was the start of an evening to forget for Atléti, as their 2-0 loss effectively ended any faint hopes of winning La Liga this season.
It's claimed that Costa, who cost Atlético Madrid over €60m in January last year, told the referee "I s*** on your b**** mother" among other things as he was sent off.
The former Chelsea star will now be out of action for the remainder of the season.
In his first full season since returning to the Spanish capital, Costa has made just 21 appearances across all competitions where he's scored five goals and claimed three assists.
It's unknown what action Atlético Madrid will look to take against Costa following his suspension, but he still has a contract at the Wanda Metropolitano until 2021.