Celta took the game to extra-time before losing 5-2, with Endrick scoring twice after normal time.
The tie was marred by controversial decisions, but Giraldez took a mature approach in the aftermath.
The 0-1 play and the previous penalty:
"It is decisive, that is clear, I will try, as I said the other day, not to talk about the referees."
What he said to the referee:
"I'm a young coach, I've been in the Primera Division for less than a year and I need to train myself to see how the VAR works because I don't fully understand it."
The key to the match:
"We haven't given up at 2-0. I'm left with the feeling that we have a team that knows what it wants, how we came together in extra time. It was hard for us to start, but we're building a powerful and strong team and I think the version of the last half hour of the game is what we want. In extra time we talked about adjusting and how to do damage but it's a shame that we failed in the last pass and we got the two great goals from Endrick and Valverde. They're all very good players."
If you have seen Celta in the next round:
"We know that Madrid has enormous potential. I think we didn't manage the 2-2 well because we could have pressed a bit harder. Then, with the talent they have, they took advantage of it. We defended well in a low block in the first half and higher up in the second. There are a lot of young players but we are happy. I think they are fair winners in that aspect."
If I would ask for forgiveness again:
"I would like to apologize again, the referees are professionals and I blame myself for my lack of training and I have to learn about the VAR, I have to train myself. The referee doesn't have to say much about it today if the VAR doesn't tell him that he needs to review. We got through almost every moment of the match and I'm proud of the players and the fans who came to see us. In a little while we play against Athletic."