Madrid earlier this week completed the £33million sign of Luka Modric from Tottenham, but ahead of Friday's transfer deadline Mourinho has hinted he is not finished strengthening his squad yet.
Jose Mourinho: "Modric's arrival does not mean the door is closed.
"Not for arrivals or departures. It is open for everything."
Reports in the Spanish media claim the Portuguese has identified Debuchy as a target as he looks to bolster his defence.
France international Debuchy: "I am committed 100 per cent to the fact I want to leave Lille, I want to discover another championship.
"The coach wants to keep me and I will not change his mind, but I will do everything I can to move elsewhere."