"What I said at half-time I told them in the last three days, instead of 10 minutes, much more," Mourinho explained. "So every time we were preparing the game and every time we were analysing and trying to reduce the unpredictability of the game, we spoke about this situations.
"What I told them at half-time was for some of you it looks like you are trying to do what I told you not to do. And it was this: I told 20 times today never play the first station ball, never, never play because it's where they want to press. It happened 20 times during the game.
"So I think some of the boys, they felt the dimension of the game, they felt the dimension of the game, everything around the game, the derby, the big game, Man United v Man City, the focus, the attention, I felt that some of the guys felt it."
"It has nothing to do with experience or age because you have the kid then in the second-half and the kid looked like he was playing in the Under-18s versus Salford City," Mourinho said.
"So it's about the individual and every individual reacts to the dimension in different ways, so it's difficult to predict.
"It only gets easier when you know the players very, very well. When you work with them one month, two months, three months, four months, you see how they react in certain circumstances, you try to get a better feeling.
"So maybe in the next big game in the Premier League probably I know who can accept well the dimension of the game, which is very important."