Much like he was under Jose, Rashford tends to play the game with a fair amount of tension and overall emotion.He's too desperate at times trying to force the issue,which was unlike him when he was first introduced into the first team under LVG. The fact United aren't particularly good at the moment doesn't help nor the fact that Rashford,and the same will likely apply to Greenword,isn't learning from a far more experienced strike partner ,and the one there is (Lukaku) also has issues with his overall game and mentality and will likely not be at the club in the upcoming season.
Overall,he's still naive with his game at present and it'll be wrong for us to go into next season with Rashford as the sole first team consistent striker.
He's still,understandably,has far more to learn in his overall attacking role but he's also in desperate need for a Ibrahimovic figure alongside him to learn from and one where he can develop at a more gradual pace under a the wing of such a forward.
Cue the usual Rashford hyperbole from the UK media suggesting the English forward should look elsewhere if United were to bring in a slightly more experienced forward,though.