I would actually like us to sell Aguero.
Of course he has done great things for us and is a fantastic player, but so much so that we bend our style to suit his game, to the extent that it is to the detriment of the overall performance of the team.
We need to play one striker up front to fully maximise our game, and Aguero has neither the height nor the goal-hanging instinct to play this role for us. To ensure our wingers' and fullbacks' attacking efforts are rewarded and that we utilise the extra dimension to the attack they can provide we need someone in the Bony or Cavani mould to lead the line for us, not Aguero.
Extra runners from midfield would help, but given his injury record and probable transfer fee set against FFP, I would sell.