The Brazil international has enjoyed a resurgence at the west London side since Sarri’s appointment as Antonio Conte’s replacement in the summer.
Luiz played a key role in Chelsea FC’s title success in the 2016-17 season before the 31-year-old fell out of favour under the Italian last term.
The experienced South American defender has forged a promising partnership with Antonio Rudiger in central defence.
Luiz and Rudiger have only conceded eight times in 12 Premier League games to secure the third-best record in the English top flight this term.
The former Benfica and Paris Saint-Germain defender has helped Chelsea FC to make an unbeaten start to the Premier League season following eight victories and four draws.
While the Chelsea FC manager has been pleased with the attitude of his squad in the current campaign, Sarri revealed Luiz has been one of the surprise packages at Stamford Bridge.
“There is an infinite passion and what I have seen so far, it has been expressed in the right way,” Sarri told Gazzetta dello Sport, as quoted by Metro.
“Correcting mistakes is the question of time. The limited time we have for [tactical] training does not help the coaches but I believe in the players.
“We must not think only of the physical component, but also of the mental component.
“David Luiz surprised me with his awareness and intelligence, [Ross] Barkley has found continuity after a long period marked by injuries.
“Willian is a player of immense quality. His style of play is perfect for England.
“And [Alvaro] Morata is a quality, fast and technical guy. He has a great sensitivity and the difficulties had hurt him.”
Luiz spent four seasons at Chelsea FC between 2011 and 2015 before the Brazilian completed a then world record move for a defender to PSG in a £50m deal.
However, the Blues re-signed Luiz in a £32m transfer following Conte’s appointment and the Brazilian helped Chelsea FC to win the title in 2016-17.
The Chelsea FC number 32 has won the Champions League, the Europa League, the FA Cup, the League Cup and the Premier League during his two spells at Stamford Bridge.
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