The 23-year-old reportedly has a £7.2million price tag on his head. Roux’s contract with Brest is set to expire in the summer of 2013.
Rangnick told the Rheinische Post: “I’ve been aware of this player for two years now, and I have already looked at him for some time.
“This is a good player and he is interesting to watch.
“The transfer is tied to several circumstances and definitely the budget. The transfer will only go through if everything is fine and agreed.”