Our defense will be better. Sure we have conceded a lot in preseason. But the real problem isn't the defense, but how well the midfielders and forwards are adapting to it.
We have to increase pressure up top. Negredo and Fernandihno do a good job of this, but the others are still pretty slow getting used to it. Samir Nasri hustles a bit more now, and Milner does his usual hard work hustle. But they don't do it as a team or in unison. We have to defend as a single unit. First, early loss of ball in the final third, all the close players must immediately either attack the ball aggressively, or aggressively attack the passing options. Thus forcing the team to punt the ball up field.
If the first wave of attack doesn't retrieve the ball back, then you fall back into a zone and close down your man hard, while the forward defending the ball, forces the player on the ball to pass it into the short side of the field. This would aid the second wave of closing down. By the end of the second wave, if we still don't have the ball, then we are back in a good defensive set, and they need to break us down proper.
We are actually pretty good once our defense is settled. We just need to make it to that point. I trust the Manager will straighten it all out before the first month of the season is done. So I am not sweating.
That said, get a good CD in. One of either Mangala, or Mapou Yanga-Mbiwa will be my choices. Mbiwa will definitely be my first choice. Like his style.