Even if it ends up that way, you don't position yourself as such. An Aguero-Sanchez swap should literally be an end-of-summer, no other option decision if it comes to that. If we feel that he wants to go to City, and he will move for free next year, you test City's resolve by saying "Give us Aguero and Sané." Let them really think about their lives.
Right now, Sanchez is more valuable than Aguero - does more and is more durable. You don't just bend over because Guardiola says so. That's punk tendency