He is similar to Martial in the sense that he never really kicked on after his early promise, although I would argue Martial's first season was better than anything Rashford has ever produced.
I feel that, if he was not homegrown, most of the CAF would have wanted him out by now. He was an exciting prospect at 20, 21, with the blistering runs and the occasional screamer. However, the hope was that he would find some consistency by now, while it has been the other way around. Good performances are few and far between with an ocean of excuses always ready for him.
My point is that, from a purely footballing perspective, I think he should be sold, but do not think this is particularly likely to happen.