Jamie Redknapp believes Chelsea's new system has given David Luiz the perfect platform to play to his potential.
Manager Antonio Conte made a change to his tactics following the 3-0 defeat to Arsenal, opting for three central defenders instead of two, and has since kept four consecutive clean sheets in the Premier League.
Redknapp believes the new formation has helped Luiz raise the level of his game, as he is perfectly suited to playing in a back-three.
"There is a hunger about this Chelsea team," said Redknapp on Sky Sports. "The manager has brought that in and the players are buying into it.
"Every single player on that pitch is working hard and there's a desire about them again. Conte has got them so well drilled. Everybody knows their job when they have the ball and it suits them defensively as well.
"Luiz looks – I'm scared to say it – like a serious defender. You've got him buying into it as well, and that was a problem for Chelsea for many years. But when he's like that, he looks the real deal."