He was saying that in order for a 5-3-2/3-5-2 formation to be effective at the top level the LCB and RCB (opposed to the central one) is in fact a specialist position as unlike a CB in a 4-4-2 you get more of the ball and need to drift more and therefore need far more ball-playing options and understand the pitch more, whilst also being defensively astute like a regular CB. Carragher disagreed.
