He has done well in Holland and now Wenger wants him to kick on with a big off-season for Arsenal.
"I have only [heard] positive reports about him. He will be with us in pre-season," the Frenchman said.
"I think he is good enough, but if he is ready enough to have a place in our team, we will ask for a work permit and try to get him in.
"What I like about Ryo is that he has good timing with his runs and understands when to go and where to go. That is something very important.
"He knows how to use his pace and he is an intelligent player.
"He is a boy who went straight from school football to professional football and straight away was the best player in Feyenoord.
"He looks a very promising boy and everybody who went to watch him has been hugely impressed by him.
"Ryo is a character and a great football player."