That is according to Blues legend and pundit Pat Nevin.
The Brazilian centre-half’s second spell at Stamford Bridge looked over last season.
Antonio Conte has fallen out with Luiz and the defender could not get into a struggling Chelsea team.
But the 31-year-old has earned a new lease of life since Sarri’s arrival in the summer.
Luiz has started all seven of Chelsea’s Premier League games this season with the side still unbeaten.
And the No.30’s turn around in fortunes in west London was highlighted in Saturday’s 1-1 draw with Liverpool.
He was awarded man-of-the-match as the Reds took 88 minutes to find a breakthrough.
Only a sublime long-range strike from Daniel Sturridge denied Luiz and Chelsea a clean sheet at the weekend.
“His display against Liverpool was totally deserving of the man-of-the-match award”
And going forward, Nevin hopes to see Sarri continuing allowing Luiz to play his own game.
“Anyone can see giving creative freedom to Eden, Willian and Pedro has been a good thing,” Nevin told Chelsea’s official website.
“But David Luiz at the back is benefitting as much as anyone at the moment from the same positivity and trust.
“I thought his display against Liverpool was totally deserving of the man-of-the-match award.
“It looks as though the coach isn’t trying to change him or anyone else into something they are not comfortable with, but just allowing them to be, and helping them to be, the very best versions of themselves.
“They are being trusted to make their own decisions and some of the ensuing passing moves from tight situations at the back had the Chelsea fans purring with appreciation.
“But, and it is a big but, you have to know when that isn’t the right thing to do and there were a few David Luiz lusty clearances that were as important and nearly as impressive as those two fabulous long passes that sent Willian through on goal.”
Luiz may be given a rest on Thursday for the Europa League visit from Hungarian outfit Vidi.
But he is expected to be in Chelsea’s backline once again on Sunday for the trip to Southampton in the Premier League before the international break.