Real Madrid striker Benzema: Nasri is Man City's best
Both teams need a win to keep their hopes of progress alive.
Real star Benzema said: "I know Samir well and he is a very intelligent and dangerous player.
"Manchester City have great players but I know from training and playing with him for France that he can be a big problem for us.
"We want to win the group and players like Samir are dangerous to us achieving that."