Wenger has increased his attacking options with the signing of Alexis Sanchez but insists Campbell will be given a chance to demonstrate his potential this season.
"He has come from a non-competitive world to a world with hyper-competition," Wenger told arsenal.com.
"He has adapted slowly, but has adapted very well, he has a very good spirit and attitude.
"He is a member of my squad at the moment, He had a good preparation and played well against Benfica.
"In training he is very focused and eager to do well. I would like to keep him."
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