The 27-year-old, who arrived at Stamford Bridge from Benfica in January 2011, and became a cult hero in West London for his all-action displays. Of course, there were some good and some bad performances from Luiz, who played either at centre back or in holding midfield, but PSG still saw enough to fork out £40m for him.
His World Cup showings once again exhibited the huge fluctuation in his performances, impressing alongside Thiago Silva before a bizarre game against Germany - which ended in a 7-1 defeat for Brazil - was largely down to Luiz's manic defending
It's therefore not much of a surprise that Blues boss Mourinho has moved Luiz on, bringing in a shocking £40m. Some believe that Chelsea's defence is now short in numbers with Luiz's exit, but Mourinho says the club won't miss him too much in the coming season.
"Last season he was not regular first choice for us. As a central defender not at all, it was John Terry and Gary Cahill the whole season," Mourinho said. "In midfield, he was a physical guy and gave us important things, especially in the Champions League when [the cup-tied Nemanja] Matic couldn't play. But this season Matic can play in the Champions League so we don't lose that physicality."
"The fact we have Cesc Fabregas moves us in a different direction. It's something that our football needs, and we want to go in that direction," added Mourinho. "David did important things here, was always a good professional and we will miss him as a good guy. But from a football point of view, we believe our squad is stronger this season than it was."
With Luiz gone and few centre backs being linked with the Blues, French youngster Kurt Zouma could be relied upon more heavily. Additionally, with Filipe Luis now the clear left back, Cesar Azpilicueta will move back over to the right hand side, meaning Branislav Ivanovic could see more time at centre back - so Mourinho could be right in his assertion that Chelsea won't miss Luiz.