The French club is desperate to strengthen their squad up front.
Sunderland are not obliged to release the 27-year-old, who has scored eight goals in 18 games for the Black Cats this season.
The French club is desperate to strengthen their squad up front.
Sunderland are not obliged to release the 27-year-old, who has scored eight goals in 18 games for the Black Cats this season.
