So how long do you give a player?
If I see that he has fundamental issue and his skillset does not fit + he shows no improvement, it can be quick decision. Like within 1 season.
But with other I can say that if they show promise and can progress, I have no issue of them being bit-part players for years.
With Royal specifically - I say sell right away. He is not a wingback, he cannot carry nor pass the ball upfield, he can't cross and his decisionmaking in final third is poor.