When Antonio Conte placed David Luiz in the centre of his three-man defence, a system that was very new to the Chelsea audience, it was hailed as a masterstroke. The Brazilian's ability to pick a pass and his overall skill on the ball helped Chelsea pull off Contre's 3-4-3.
But there was always a problem - Luiz's performances at the back went from fantastic to mediocre by the second season and what followed were questions as to who will occupy a similar role for Chelsea in the future. Ball-playing centre-backs were becoming the rule rather than the exception and Chelsea also had to find a way to replace the Brazilian's skillset when he ultimately left the club to join rivals Arsenal.