Fair enough but De Gea should be the exception to this rule as he is absolutely diabolical at them. Ole afraid to make the big call.
I don’t think it’s about fear but loyalty and respect, which are big contributors to good camaraderie and a positive environment. Ole has been widely praised as a good man manager, and it’s the thing that he most valued in Sir Alex.
We have two keepers at a similar level. They were told that the one that earns his place in the first team will play the league games, but the backup won’t be pushed to the side, they are too good for that, so they will play the cup games. All of them. If he were to disregard that commitment in the moment, it would be disrespectful to the individual, having lasting effects on their morale, but it would also send a bad signal to the rest of the squad. They wouldn’t trust him.
I don’t think Ole is a good manager but he has the trust of his players. If he threw that away he would be putting short term gain ahead of long term pain. Strategically it doesn’t make sense. It just isn’t as simple as this one moment. That’s why keepers generally aren’t pulled out at the last moment. It would be damaging in the long term.