And Song didn't go walkabout last season. He was busy being the league's 4th most creative player, creating more goals than Rosicky, Ramsey & Arteta put together.
No doubt his attacking play was hit and miss, to say the least, but it's fairly obvious he was picking up slack created by those around him not pulling their weight.
We've seen Song play a more outright-defensive role in the past, and on occasion last season too. You won't hear me say this often, but I think it's fairly obvious that if the manager wanted to sort this out, he could - Arsene's not sitting powerless on the touch line, he knows where Song's playing & he's clearly happy with it to some degree, because as annoying as the missed passes and the absence from the midfield have been at times this year, the role Song's played has been pretty much essential.
Personally, I want to see him move backwards again - but that will involve us finding more diverse avenues of attack next season. The wingers and other midfielders will need to contribute more than nothing. Podolski & Oxlade should help there, Giroud may take some of the burden off Robin, and maybe Theo / Gervinho will show a bit more consistency. Having Jack back too will also give our team better structure than it had when Ramsey was around.
Personally, I had hoped that (assuming no change of formation) we'd play next season with two of Song, Arteta & Wilshere in a more withdrawn role next year, and sign a Hazard, Kagawa, Götze type to play in front, and help us control the final phase in a way we didn't really last year. Failing that, I'd still be happy enough to play Arteta & Song behind Wilshere (or occasionally maybe Ox) and gamble that Jack can make the step up, so long as RVP stays & Podolski hits the ground running. We'll control the game better, and threaten in attack a lot more - and consequently, I don't think you'll see Song 'going walkies' quite so much.
