Luiz completed a stunning return to Stamford Bridge on transfer deadline day as Chelsea paid Paris Saint-Germain £30m to re-sign the defender that they sold in the summer of 2014.
Luiz made his second Chelsea debut in Friday night's 2-1 defeat to Liverpool in the Premier League, and Hazard has branded the Brazilian international "a warrior" who brings 'a winning mentality'.
"Everybody is happy to see [Luiz] back. On the pitch he is a warrior. He brings that mentality. He wants to win everything. This is what we need," Hazard told Chelsea TV.
Chelsea will travel to English champions Leicester City in the third round of the League Cup on Tuesday night.