With the points difference between themselves and Barcelona now standing at 16, Real Madrid's LaLiga title hopes are becoming fainter and fainter, and the club has a clear weakness on the flanks with Neymar and Kylian Mbappe still to face them.
Whilst it's just one of numerous issues within Zinedine Zidane's squad, the collective lack of form and confidence amongst the club's full-backs is only going to play into the hands of the Parisian club's dynamic duo.
Dani Carvajal is suspended for the first leg of the tie with Paris Saint-Germain.
Achraf Hakimi and Marcelo seem the most likely to start, but the pair performed awfully in Sunday's draw with Celta Vigo.
The young Moroccan has a great future ahead of him, but at 19 years old you must have patience with him, because at this moment he isn't ready to go toe-to-toe with Neymar on the biggest stage.
Nacho is an alternative option at right-back for the clash with the French giants, however, this depends on the fitness of both Raphael Varane and Sergio Ramos.
This lack of depth in defence is a real problem for Zidane this term and it's no surprise that there have been rumours linking Los Blancos to central defensive reinforcements in January.
The French coach once again saw his changes have next to no impact.
Withdrawing both Luka Modric and Isco in one swoop sounds crazy on first hearing, but he was forced to stop the flow of attacks that was coming down either flank.
Iago Aspas enjoyed yet another fine individual display, his current form placing him amongst the best players in Spanish football.
Despite his attempt to dive to win a penalty, he was a constant threat to the Real Madrid defence and was key in distributing the ball into wide areas.
Gareth Bale has long been criticised by supporters at the Estadio Santiago Bernabeu and there are those who believe he is overpriced, those who wouldn't have renewed his contract and those who take aim at him for not being fit enough.
His brace on Sunday illustrated his true quality, and the pass from Isco to the Welsh international for his second goal was sensational.
An example of Los Blancos at their best.
We live in an era where VAR is seen as the saviour of professional football, especially at a time when human errors from officials are put under such intense scrutiny, however it must be noted that none of Monday morning's papers will bear the names of Jorge Bueno Mateo or Fernando Tresaco Escabosa.
These are the assistants to Jaime Latre who got two crucial offside decisions correct; the margins on both were so small that it truly was an example of phenomenal officiating.
If officials are criticised so severely when they make a mistake, it's only fair that when they produce a fantastic performance that they are recognised for it.