Arsenal boss Arsene Wenger was delighted with four-goal Yaya Sanogo after their stunning 5-1 Emirates Cup win over Benfica.
The Frenchman never found the net for the Gunners last season.
Wenger said: "Sanogo came last year on a free and we worked very hard for six months with him and from January onwards he was slowly getting better, now that we have worked very hard with him, we want him to stay here.
"Sanogo was injured for basically two years before he came to us. If you look at his goalscoring record before he got injured, it is quite frightening. For a while when he came back last season, he could not score. You could see when he scored the first goal today, suddenly they can rain in.
"He has a big future here, of course, he is 21."
Wenger added: "Campbell has done very well. I like the way he plays.
"He is good on the ball, creative and collectively as well he has a good balance between individual skill and collective attitude - that's not easy to find and there is no reason to let him go."
