Unai Emery was reunited with David Luiz this week as the Brazil defender became our sixth summer signing, arriving at London Colney on transfer deadline day.
Our newest recruit and our head coach have worked together before, and Emery thinks he'll be a major asset.
"We worked for two months together at PSG and then after three matches, the club and he decided to sign for Chelsea," he said.
"Now is the same. It's a very good and big opportunity for us and also the fact that he decided to change Chelsea for Arsenal is an important step.
"He wants to do something important with us, to help us do something important in the present, in the future.
"He has experience, he has quality in the build-up and he's a good defender. He's coming here to help us with his capacity and quality."
Copyright 2019 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source.