This isn't Football Manager though, or FIFA, where players make more-or-less linear progress until they achieve their potential. Human beings don't work like that, and because of that some will fall through the gaps. I firmly believe that if Martial hadn't have been injured that time, Rashford would never have got his chance, and would either still be in the reserves, or sold.
When he played for us, Michael Keane did not look terribly good, and did not take his opportunity to impress. A couple of clunkers apart, there are very few youth products that have gone on to excel in that way Keane has, to the point where we're looking at bringing them back.
Are you furious about Danny Drinkwater as well?