The only question to be asked if we lose him is "Lee, why did you turn down the chance to develop playing first team football and choose to sit for a long spell on the bench elsewhere?"
The contract has been offered, and given our new club strategy and finances, I imagine it is a generous one for where he is in his career. What we can't do is force him to sign it or stop his agent from shopping him around.
I'm not usually too upset when someone leave us - it's the nature of the game. In Erwin's case, I would be more upset only because we stuck by him through 2 serious injuries and then bumped him up to the first team.