Lampard has been unhappy with the number of games he has missed this season and last week admitted his relationship with manager Andre Villas-Boas had "not been ideal".
Defender Luiz has publicly backed Villas-Boas' stance, telling Portuguese newspaper O Jogo: "No one has to be someone's father or son in a football club.
"There are no privileged people there. He [Lampard] simply has to listen to the coach when he gives orders and take them.
"No player can forget that they are just an employee of the club."
Speculation is rife about the future of Villas-Boas, who this week admitted for the first time that he could be sacked as manager.
"Last season, there were teams who were in a poor position in the table, and no one talked about it," Luiz said.
"It is a lot easier to talk about Andre, because Chelsea are a big team who always fight for the first place. And when they are third or fourth, it gets easy to slam the coach.
"But Andre has an immense capacity, he is an excellent person and I am sure he will have a great future at Chelsea."