The 35-year-old believes the Brazil international also needs to leave so that the club can bring in younger and better players that would help Arteta form a team as solid as Jurgen Klopp’s Liverpool in the next few years.
Bentley added: “I was surprised at the new contract. I don’t know if it’s because of a lack of preparation in getting players in but the recruitment with the back four is a problem. It always has been. David Luiz is problematic.
“He’s a great technical player but if you want to bring the youth through and create a winning mentality is he really the type to help with that? I was surprised at the new contract.
“I don’t know why they didn’t look to bring in Gary Cahill or someone like that, over David Luiz. Maybe Luiz is more fashionable.