The Moroccan international was a mercurial force in the Championship last season with 19 goals and Wenger says the 22-year-old must now find consistency.
"He is a very talented football player," Wenger told arsenal.com. "He has shown here that he has talent, that I knew. But he has to produce these kinds of performances on a consistent level.
"No [I have never tried to sign him]. He was in Lens and then he went to Tottenham. He is a good player with good potential but he has to produce that week in, week out."