Brin I'm fairly sure if Evans stays the crowds will plummet because I don't think many people believe he has the capabilities to build a successful team anymore.
Added to that, a lot of people seem to dislike him intensely and didn't want him to come back to the club in the first place.
TS needs to make his decision based on business logic and not be blinded by any misguided sentiment for someone you say he considers to be a friend.
I wouldn't like to guess what he'll do because he's in a really difficult position and whichever way he jumps it could all go horribly wrong.