Garnacho doesn't know how to play in a team, he is too egoistic to achieve good results with him. And as for Rashford, he does not show a stable game, and recently it is clear that he has some grievances against Amorim, who may leave him out of the squad for the game. And considering that Amorim will want to get several players from Sporting to Manchester United, Garnacho and Rashford will be better off finding other teams where they will be valued more.
Garnacho is still young, that's why he act like that. Many great young people ever had star syndrome, if Garnacho can control his ego, he will become a great player. However, I still keep imagining what if Greenwood not beat his girlfriend, that guy is a gifted player, he might be as good as Vinicius right now.
Even though he already not playing football for many years, but his first season with Getafe was quite good and his performance in Marseille is really amazing.