Marseille are currently sixth in Ligue 1 and the defender has been strongly linked with the likes of Bayern Munich, Arsenal, Napoli and Monaco.
“Leaving in the winter? I am no coward,” he told France Football.
“I am not happy with what I have showed recently, so in such circumstances I won’t leave.
“I owe a lot to l’OM who made me make a name for myself. It is very important for me to find again my best level first.”