But Les Girondins president Jean-Louis Triaud admits the lure of a lucrative testimonial for the 30-year-old, who made the move to Old Trafford in 1999, has put the brakes on the switch.
"There are several targets for the left-back role," Triaud told French radio station RMC. "In that position, above all there was one who was his (Blanc's) first choice and that proved to be impossible.
"Yes, I think the possibility of Mikael Silvestre coming here has ended.
"He has a salary at Manchester United that he has no reason to forego. Moreover, after 10 years at that club, there is a tradition that a friendly match is organised for the benefit of the footballer with the revenue going to him."