Vinicius now faces a nervous wait for the ruling of the disciplinary committee, which could see him miss Real's fixture with rivals Barcelona on October 25th at Camp Nou.
The Brazilian thought he had scored Real's second goal but his effort was disallowed after a VAR review found he should be dismissed for pulling Nathan Saliba's hair in the build-up.
After the match, Vinicius, who came on in the 52nd minute and was red-carded 20 minutes later, posted on social media, saying, "sorry to the team and the fans".
Spanish Football Federation regulations state that pulling an opponent's hair is regarded as violent conduct.
The sanction for violent conduct without causing injury to an opponent (Article 130) is a ban of one to three matches.
Real's next three LaLiga games are against Sevilla, Barca and Racing Santander, but missing El Clasico would be a bitter blow for the 26-year-old Brazil international.