Luiz is looking forward to welcoming Oscar to the club and helping his Brazilian international team-mate settle in England.
"Oscar will adapt quickly, he has a lot of Brazilians here at Chelsea which will make it easy for him," David Luiz told the official Chelsea website. "We will all help him to adapt as quickly as possible to London and the Premier League.
"I spoke to him before he signed, I told him Chelsea is a great club and that it is a big opportunity in his professional life, to show his football to the world. Chelsea is one of the top five teams in the world and I think it was the best choice for him."