He wrote in the Mirror: "I know he has scored against Schalke in the Champions League, against Everton and the likes of Spurs. But now you're looking to see what he does against the likes of Chelsea, Manchester United and City.
"He will definitely have to learn the position and defences will make it hard for him by dropping deeper.
"But he has been on at Arsene Wenger to be allowed to play through the middle and he is doing really well.
"So let's give him the time to learn how to play the position at this level."