It's now official. Real Madrid have been disqualified from the Copa del Rey after playing Cheryshev against Cádiz when he was suspended.
Real Madrid can still appeal this decision but it is very unlikely that the Spanish Federation will change it.
Therefore, Real Madrid have lost their first title of the current 2015-2016 season in December, and it hasn't even happened on the field. One could think that Madrid have more than enough men taking care of these issues, so it's definitely surprising to see Madrid making mistakes of this nature.
Real Madrid will not need to play the second leg against Cádiz and their schedule next January will not be as tight as it could have been, but the Liga BBVA title is already 6 points away and Madrid will need Barcelona to drop some points sooner rather than later.
Either way, this is the kind of error that could and should get people fired from their jobs. Who should be blamed for this?