Luiz was a surprise deadline day signing by Chelsea, as they brought him back to Stamford Bridge two years after he left to join PSG.
He fills a much needed need for a new centre-back, with only captain John Terry and Gary Cahill available to new manager Antonio Conte in the first few weeks of the season.
His arrival has also seen some suggestion from fans that now they will be able to play with a back three, something which Conte used with Juventus and Italy, and Luiz told the club's website that he is more than comfortable in either formation.
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He also added that without the Champions League this season he hoped he could help the club win a domestic treble.
"I started playing three at the back with Vitoria in Brazil, but it doesn’t matter where, I want to help and when I am in the team I am there to try to help.
"The coach is an amazing coach, he understands a lot of tactical things and I know he chooses every match the best line up, so if he needs to play three, four or two, it doesn’t matter, I am there if he wants me to play. In different positions I am available.
"It is time to do it! [win the league] And I hope it will be this year. I am working hard for that and this is our goal this season. We don’t have the Champions League to fight for so for sure we will try to win the Premier League and both cups."
Chelsea fans are delighted with the return of Luiz and he admitted that the decision to return was entirely down to him.
"It was my decision, yes. I really wanted to come back because I spent an amazing time here. I loved to be here and that is why I want to come back."
During his time at PSG Luiz faced Chelsea in the Champions League and whilst his emotional goal against his former club captured the headlines his battles with Diego Costa were one of the highlights of the tie.
Chelsea's Diego Costa clashes with PSG's David Luiz
Image credit: Eurosport
Luiz certainly showed no ill will towards Costa and spoke about his excitement about being able to play with the forward now.
"He was an amazing player when I was playing against him. He is a guy who gives everything for your team and now I am on his side, for sure I have a great striker for my team and with the spirit of love for football, with passion, so I am happy for that."
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