Los Blancos are undoubtedly the greatest team to have ever graced Europe's most prestigious club competition, but their 2-1 loss in the 1st leg at the Santiago Bernabeu has pushed them to the brink of elimination.
After Isco gave the LaLiga champions the lead in the 60th minute, Kevin De Bruyne took centre stage as Madrid collapsed. Gabriel Jesus shrugged off Sergio Ramos to head past Thibaut Courtois in the Real Madrid goal, before Dani Carvajal brought down Raheem Sterling in the box with De Bruyne dispatching the ensuing penalty.
Things went from bad to worse for the hosts when their captain Ramos was given a straight red for bringing down Jesus, who was bearing down on goal.
With a 1-goal deficit and 2 City away goals to overcome at the Etihad Stadium, Real Madrid and Zidane have their task cut out for them.
It would be foolish to count them out, though, and here are 5 reasons why they could pull off a comeback against Manchester City.
#5 Real Madrid's defense has been rock solid this season
Although Sergio Ramos will miss this game due to suspension, the defense is more than capable of stepping up to the plate in his absence.
Raphael Varane has been as assured as ever this season and will welcome his new role as the leader of the back-line. New signing Eder Militao has excelled whenever he has gotten chances, with his recent performances in particular very encouraging. Both centre-backs are fast and strong - qualities that will be vital against pacy wingers like Riyad Mahrez and Raheem Sterling.
Right-back Dani Carvajal has perhaps been Real Madrid's most underrated player this campaign, while Ferland Mendy (expected to start ahead of Marcelo) has been resolute in defense and since the restart, potent in attack.
Thibaut Courtois won the Zamora Trophy (for most clean sheets) in LaLiga, and Casemiro has been an absolute rock in front of the defense.
In a game where the first goal could completely shift the momentum, Real Madrid's airtight back-line could pave the way for the attackers to mount some serious pressure on the weak Manchester City defense. Speaking of which.....
#4 City's defensive issues could play into Real Madrid's hands
Manchester City did manage to keep two clean sheets in their final two Premier League games, but they've been plagued by defensive issues throughout this season.
Their best centre-back in Aymeric Laporte suffered a long-term injury that put him out of a major part of the campaign, while John Stones and Nicolas Otamendi have been far from solid. Fernandinho and Eric Garcia have played at the position, but irrespective of who partners Laporte, the pace of the Real Madrid forwards will trouble them.
Perhaps more concerning is the full-back problems that the Cityzens have faced. While Benjamin Mendy is suspended for this game, Oleksandr Zinchenko's inexperience could mean that he is not trusted for this high-profile match-up.
Joao Cancelo has performed decently whenever he has slotted in at left-back, but the Portuguese hasn't exactly settled into life at Manchester. Kyle Walker is a shadow of the player he was when he signed from Tottenham, and manager Pep Guardiola's expensive full-back rebuild has hardly gone to plan.
Against a Real Madrid team which thrives on attacking from the wings, Manchester City could be woefully exposed. With their wingers also not offering much defensively, Eden Hazard, Rodrygo, and Vinicius Junior could run riot at the Etihad.
The stats back up these claims - in 5 Champions League home games under Guardiola, City have conceded 10 goals.
Also check out: the Champions League Winners by season