Well, that was a waste of a perfectly good '5' !!
Come to think of it, I remember Liverpool having a midfielder wearing no.5 in the 70s or 80s - can't remember who it ws though.
Back in the day when the players on the pitch were numbered 1 to 11, it was usually numbers 5 and 6 at CB, but not always. Playing alongside Brian Labone at CB for Everton was no,10, John Hurst, which always seemed a bit weird!