The 27-year-old is out of contract at the end of the season and is expected to leave the French capital.
Arsenal have been strongly linked with a move for the Frenchman and it has even been claimed the Gunners have sent a contract offer to the defender.
His agent, Kia Joorabchian, is said to be currently negotiating with the club.
But it seems Chelsea are ready to enter negotiations over a possible deal.
Being a free agent, that would give Chelsea money to spend elsewhere on the squad.