He's never played centrally in his entire career, so I'm not sure why everyone's saying he has to play there.
Where do you think he played tonight out of interest?
He played as a left footed RAM for Monaco, most often cutting inside so the full back could overlap. City tend to play with 'correct' footed wingers who take on the opposition fullbacks to aim to get into a crossing position. Bernardo having to cut back on to his preferred foot slows down those type of attacks.
So we could change our style of play to give Bernardo more support from the full back when he's on the wing. But why do that when our style of play has been so devastating this season? That leaves the alternative of finding places in our current system that Bernardo's style of play suits. I personally think he's closer to Silva in style than any of our other senior players and should be tried when David needs a rest instead of Gundogan. He might also do better on the left flank where he'd be on his correct side.