That is the view of player-turned-pundit Danny Higginbotham.
The Blues re-signed the centre-half from Paris Saint-Germain for £30million at the end of last summer.
But his return did not start off smoothly as Chelsea were beaten 2-1 at Stamford Bridge by Liverpool and 3-0 by Arsenal at the Emirates in Luiz's first two Premier League games back at the club.
Antonio Conte subsequently reverted to a 3-4-3 system which his team have flourished in, with Luiz the central figure in defence.
David Luiz has been a regular for Chelsea under Antonio Conte
My first thought when Luiz rejoined Chelsea was: Antonio Conte is going to play a back three
Cesar Azpilicueta and Gary Cahill have been regulars either side of the Brazil international, which has seen Chelsea rise to top of the table.
"My first thought when Luiz rejoined Chelsea was: Antonio Conte is going to play a back three," Higginbotham wrote in his column for The Sun.
"That is what he did with Juventus and Italy and the defeats to Liverpool and Arsenal were a blessing in disguise because they allowed him to make the change sooner.
David Luiz exacted his revenge for Chelsea in their reverse game at Liverpool by scoring a free-kick
Get Quotes on Home Insurance
David Luiz gives brilliant response when confronted by angry West Ham fan
Mon, March 6, 2017
Chelsea defender David Luiz is spotted giving a superb response to an angry West Ham United fan who invaded the pitch after Eden hazard's goal at the London Stadium
Marc Atkins / Offside
1 of 8
David Luiz is spotted giving a superb response to an angry pitch invader
David Luiz showed again in Chelsea's win at West Ham on Monday he is much sturdier now
"The system suits Luiz — and Chelsea — very well. Conte has obviously done a lot of work on the team’s set up.
"At West Ham, no player was ever isolated. They attack and defend together as a unit.
"In a back three, playing like a sweeper, Luiz has less responsibility AND more insurance because he has two other defenders around him."
Chelsea now sit 10 points clear of second-placed Tottenham, with Liverpool and Arsenal in fourth and fifth respectively.