With Edouard Mendy making his Premier League debut in goal, and Thiago Silva at the heart of the defence, it was down to Kurt Zouma and French-speaking Azpilicueta to help out with any instructions for victory over Crystal Palace.
"Yes it's true, we were communicating in French," Azpilicueta told the club's website.
"I speak French, as does Thiago, and obviously Kurt does as well. It was a good way for us to talk at the back. Edu [Mendy] in goal speaks French too, so it was the best way for us.
"We try to help out as much as possible with the players that don't speak English at the moment and it is no problem for us. Thiago also speaks the same language as Jorginho, so he can communicate with him too.
"I think language is secondary though. Football is a universal game and for people like Thiago, he's been around the game for a long time and can lead others even without speaking the language so well.
"We want to make the adaptation as easy as possible for the new players and if we have to speak French in defence until the guys understand English, then that is fine."