^ That is because he is basically a winger, not a defender I really hate this trend of using midfielder at CB position. It is ok to have one or two like Mascherano or Busi to cover in emergency but shouldn't be followed as general policy.
No confidence in his defense, none
Thing is, we need our fullbacks to have an extremely well rounded attacking game in order to carry out our gameplan. How many great defenders can do what the likes of Alba, Adriano and Alves does for us in attack? It's really a trade-off: What do we need the most, defensive stability or attacking outlets? The way we play, I think it's an easy answer.