Wenger said: "He is going through a good spell. He had an indifferent spell at the start, but now he has adapted very quickly.
"He is quick, strong, brave and that's the kind of competition you want to keep quiet in the Champions League.
"You must be particularly careful when he is away from home. You do not want to give him any counterattacking chances. He and Steven Gerrard are both very quick on the break."