Can't speak about everyone but I would say that for Rashford, you kind of expect this for a young player in his second season at a top club. He came in with no expectations and had a fantastic debut year. He comes into the second season with expectations which will surely pile on some pressure. Added to that is the fact that he hasn't started centrally for a stretch of games. Most of the season he has been playing off the wing. So when he comes in as the central striker, adding all of those various factors, he's not going to be playing on instinct alone (which is what strikers need to be doing if they're scoring consistently). He just needs to develop mentally to adjust to the pressure in my opinion. I think he'll be fine next year.