Rashford can't afford to be lazy if he wants to become a key player in the Barcelona squad, and he must also be able to work with the existing players in the squad. If he continues to show his ego during any match, he may not get more minutes in the Barcelona team and won't be signed permanently by Barcelona after his loan period ends. I also want to see how Rashford adapts to the other players at Barcelona, as they were generally good players, judging by their performances last season.
I really hope Rashford comes good for Barcelona. I mean, if he becomes so good that they will have no choice but to shift Raphinha to the middle to play behind the striker. I would like to see how an attack of Rashford, Yamal, Raphinha and Lewandowski will look. If they can find a way to make that attack work and have two midfielders like Pedri and Frenkie/Gavi/Casado/Bernal to hold down the midfield, they might have a very good team.
The thing is, I don't have much faith in Rashford. The Rashford of the last 2 seasons has not been all that. He has not had a good season in 2 years, and with that kind of inconsistency, there may be a problem. The good news is, he is extra motivated to succeed in Barcelona and prove to himself and others that he still has it, so he will work hard, but no matter how hard he works, if the talent is no more there, then its not there.