Diarra said: "There were some good and bad moments at Chelsea but I changed because I am not a right-back.
"I want to play in midfield, to touch the ball and pass to people. Playing right-back is just running up and down. When I was at Chelsea, the players there said Claude Makelele was my father. But I want to show I am Mr Diarra, not the new Makelele.
"Arsene Wenger knew the player I am when he signed me and, at 22, I cannot wait as I have in the past.
"I know Arsenal are a very good team, top of the Premier League and playing good football. But I want to play."