Real won 2-1, thanks to goals from Kylian Mbappe and Vini Jr. Williot Swedberg struck for Celta.
Ancelotti was satisfied with their performance afterwards.
Tough victory?
"It was a competitive, hard-fought and difficult game. The merit we have is that we competed well until the end. We could have played better, but the team was committed. We lacked balance at the start and the goal we conceded could have been avoided. We need to be more attentive, especially on the counter-attack.
"We got three important points thanks to a fantastic pass from Modrić. He always contributes and helps, whether he starts or comes off the bench. His quality is very important to us. He changed the pace of the game and was very important."
Modrić performance?
"There is not much more to add. He's still a fantastic footballer. He's not a child. He's an extraordinary professional, who works very hard. He's a very calm man with character. It is and has been a good thing for Real Madrid to have a player like him."
Bellingham position?
‘Bellingham's position has changed. The idea was to go in more with him from the second line on the right wing because in previous games Celta have suffered with balls to the back post. I liked Bellingham a lot today.
"Tchouameni with the ball was between the two centre-backs and that's where we had a problem of balance in the first half because without the ball he had to get forward and that's where we lost our shape a bit. In the second half we changed a bit and Tchouameni was more on the right.
"What we didn't work on was the opposition losing the ball, Tchouameni getting forward and the centre-backs staying back. That's when we suffered on the counter. With a different formation to the opposition, you can play with the pivot in front of the two centre-backs."
Bellingham scolding Vini Jr?
"He's contributing. I didn't see what happened with Vini Jr, but he has a lot of guts and a strong character. After the game I saw them talking and laughing. I don't think there will be any problems."