Sanogo told France Football: "I told my agent the choice would be made between these two clubs. Lille's coach Rudi Garcia called me all the time. I hesitated a lot.
And it was during that meeting that Sanogo made his decision to join the North London club.
"Wenger told me I would get opportunities and reassured me about my injury. He told me he had followed me for years. That meeting was very important and today I am an Arsenal player," said Sanogo.
"It will be an amazing adventure. I am just eager to start in one of the best leagues in the world. It is a dream that has come true."