David Luiz left Chelsea to join Ligue 1 champions Paris Saint-Germain on a five-year-deal for a fee reported to be in the region of £50million.
That move ended the 27-year-old's three-year spell at Stamford Bridge, and it is a piece of business from PSG that has come under increasing scrutiny following the centre-back's performances at the World Cup.
Indeed, David Luiz was heavily criticised in the wake of the host nation's humiliating 7-1 semi-final defeat to Germany, and the 3-0 third-place play-off loss to Netherlands that followed.
And Mourinho has now given his assessment of the former Benfica man, stating that Chelsea do not need the services of David Luiz - who can also play in midfield - to be successful in 2014-15.
"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.
"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."
