Arsenal have confirmed that Edu will leave his job as sporting director with immediate effect and Martin Keown has suggested a theory as to why it’s happened. Edu has been confirmed as leaving the Gunners after a successful period alongside Mikel Arteta in reshaping the club’s fortunes on the field. The Brazilian is widely lauded as the man who changed Arsenal’s transfer policy for the better and the last few seasons have seen a number of his signings pay off. However, TBR Football understands Edu became frustrated with life at The Emirates, while we also understand Edu has been talking to Not…