I'd do Green for Asik straight up. I like Jeff, but he's not a championship player. This team needs a defensive center as much as anything. I know their defense has been decent for the year, but they have a definite weakness in the middle. Big Baby should not beat us.
A replacement for Jeff can be found over the summer. Between all the 3's in the draft as well as hitting free agency this year, that is the most fillable position. Asik might not be the best thing ever, but he's probably better, at least for next year, than anything else available out there (unless you think Greg Monroe is actually available). If Danny's trying to put the team in contention next year, it's better to fill that hole now and the small forward hole later. If he's not, then sure, hold out for a draft pick.