Emery admits he had a conversation with the Brazilian before agreeing to let him leave.
"I told him I did not want him to leave and that was important. But if he's not happy and he thinks it is better for him to leave, I respect that. That's what I said to the club.
"Then we found it too late to sign someone and it was better to wait until December. And we have (Presnal) Kimpembe playing well. He must be given confidence. Marquinhos returns, Thiago Silva is ready to play.
"If all goes well, they are the three. And Serge (Aurier) has the ability to play centre-back. He can do a good job in this post. I talked with him and he is ready to show that versatility."