Manchester United are currently leading by a goal to nil, Sancho with the goal, RashFord would have fired the ball towards the Goalkeeper. That's the difference between him and Sancho. With the way Manchester United are playing without Ronaldo and Maguire and they keep winning, both dude will stay on the bench for long
CR7 isn't concentrated with all drama about him leaving the club. After the closure of the transfer window, he should return to his form and I assume Ten Hag will give him chances to do it more than Maguire for sure who proved that the best position for him is in the benches..for now.
After 5 rounds, the difference between ManU, Liverpool and Arsenal or City is more than 4 points up to 7 which is relatively huge, considering how they were winning. Few goals difference, last minutes goal..
In this case it's very likely that when he can't leave and the transfer closes he will play even better because for now it's clear he doesn't seem to be playing loose in every game he plays.
He has to be big-hearted now and the fact that he isn't going anywhere this season should be used as an excuse for him to play well because indeed it will also be good for him in the future especially when his contract runs out at United.