There's absolutely a good reason for this - hoping to extract higher wages from City than you previously agreed to if (Sanchez) you eventual sign for City.
But that's precisely why we're no longer interested - screwing around after having previously made a promise is a huge character flaw. One that's rightly (IMO) perceived to be so bad by our management, that once you show this flaw, you've shown signs that you'll be far too much potential trouble - no matter how talented you are - than you're worth in our side, no matter what the price.
Give your word - live by it. Otherwise, we're no longer interested. This is absolutely Pep's philosophy and is at the least backed up by Trixi (but I think it's his philosophy too).
You can play poker with some other teams - but not with City.