It's a depth chart. Its not simply a list of players and where they NATURALLY CAN play, but also includes where they COULD POTENTIALLY play if required.
The idea is to identify areas that 'shallow'.
There are going to be times when we need other options because of injuries or suspensions and that's when the 'could play' options play a role. Perhaps they should be indicated by brackets as a secondary role, but they should be there for when the need arises. AN obviously values these 'options' as he indicated today when he said that Wisdom can play in a variety of positions. One of the reasons we paid the reported £7m for Brady is his ability to play in a variety of different positions, which is why he acknowledged this in his interview when he said that he was happy to play wherever AN asked him to play.

