Rashford doesn't really need to prove anything to anyone at this point. Dude has been a solid striker for many years. Just because he had some deals with injuries for a while now, doesn't suddenly make him a bad player. Unfortunately this is a thing only in EPL, look at Milan and how they are keeping Zlatan at 41 years old and like 10 months missing the game at the same time, that should tell you something about Loyalty. EPL is not like that, you could play from 19 to 29 and provide a lot of great things for a club, but if you have one bad season, one injury, one bad summer camp and BAM! you are totally gone for some reason.