According to the new rules introduced by IFAB, a field player must leave the field for a minute after a treatment for an injury that did not result in a yellow or red card. This rule was applied by referee Manuel Jesús Orellana Cid during the match, causing confusion among the Real Sociedad players.
The new rule was introduced to prevent game disruption, but it seems that Real Sociedad were not aware of the new regulation. Goalkeeper Álex Remiro was injured during the match and received treatment, after which the referee applied the new rule and asked a player to leave the field.
The confusion led to Real Sociedad's captain Igor Zubeldia receiving a yellow card for refusing to leave the field, while the head coach Pellegrino Matarazzo and his assistant John Maissano were both sent off with a red card for their reaction to the situation.