Sir Alex Ferguson was so glowing in his praise of Spanish goalkeeper Diego Lopez that he claimed if Iker Casillas had been fit then United would have stood a better chance.
It really underlined the stunning performances Lopez made in both legs and the contribution in keeping Madrid in the tie, denying Robin van Persie on six occasions over the two matches.
Lopez was 'just' an emergency signing by Real, signed in January from Sevilla for £3 million, after first choice Iker Casillas picked up an injury.
Casillas had been in and out of the side prior to that, with Mourinho preferring Adan for a run of games, but it was clear he was simply challenging the Spanish number one because as soon as it emerged Adan could be his option against United, he rushed into the transfer market.
Lopez had only been at Sevilla a matter of months, signed from relegated Villareal the summer before, where he had previously faced United and kept two clean sheets.
Now Jose Mourinho is going to have to make another decision, with Marca reporting yesterday that Iker Casillas had participated in light training for the first time.
An attendee of the gym every single day since his injury, it's clear Casillas is not rushing back to sit on the bench, he wants to go back and earn his place in the team.
So the question is whether Diego Lopez, the 'Hero of Old Trafford' should retain his place ahead of Casillas when he returns, likely in two-three weeks time?
Casillas is an influential figure in the Real dressing room and popular teammate, but Mourinho showed before his injury he was not afraid of dropping him.
Lopez' performances have been so outstanding that the goalkeeper simply has to continue between the sticks in the short-term, it was not just the Champions League encounters, but the two winning Clasico performances which bolstered his credentials.
The question may be intensified by the Champions League draw. If Real draw Barcelona, will Lopez get the chance to repeat his heroics, or will the intensity surrounding the ties accelerate calls for Casillas to be re-integrated?
It's hard to see Lopez being dropped instantly, but with a lot of football still to be played, and several La Liga games which will amount to dead-rubbers for Real with Barcelona effectively champions already, there will be plenty of opportunities for Casillas to stake his claim.
With the ultimate goal of playing in the Champions League Final, winning his place back could just be the biggest challenge he has ever faced in his Real Madrid career to date.
How should Mourinho handle the 'keepers when Casillas returns? Should Lopez keep his place?
image: © illarterate