They are struggling in 16th in Ligue Un and see Digard as their saviour.
Digard only joined Boro at the start of last season, signed by former boss Gareth Southgate as a replacement for Lee Cattermole.
Coach Didier Olle-Nicolle: "We must recruit two players, a central defender and a midfielder and we are working on that now.
"Two of those are Didier Digard and Renato Civelli, there are others too, but we hope to do these shortly.
"This could be done this week. Digard is expensive, but it could be done and we are discussing it.
"No matter what happens, I think they would be two loans with an option to purchase."