According to a news report, Rashford won't immediately be a key starter in the lineup. However, this doesn't mean his role isn't important. He will be a key player on the bench, available for various rotations.
Source: ansi Flick on Marcus Rashford Is Barcelona going to add more pains to the young man's life or should I call it regret? If Flick thinks Rashford isn't going to be a started they should have left him to hang on what Manchester United are going to feed him with, he's a baller and a starter...after all Barcelona have better players on the pitch and on the bench as well so why make Rashford a player to call "IF" ("if someone is injured or unavailable he can play")? I still wonder why Aston Villa didn't go for the English man before now after all he did better for the club last campaign and as for him playing for Barcelona or should I say him sitting on the bench for Barcelona, I don't think he'll have anything big to show or convince them that he deserves to start for the team, we might see less of him next season but if he knows about this development and agrees with it then he's the one who choose to be a bench starter that isn't sure of starting 25 games next season.