He has played this formation before if he expects the opposition of sitting back and using the counter to score, so not to waste an extra defender he loads up front, but normally you would expect two strikers where this time he has employed another midfielder and is looking for goals.
Magic moment
Wonderful from Silva, who releases Sane with a gorgeous through-ball. The German latches onto it before crossing for Aguero, who beats he defender and converts at the near post.