This may look like a good trade on paper, but does it damage the team chemistry in Boston?
I'm not going to get into whether this makes sense from a baseball perspective as far as bringing in players that can help Boston win; I think it opens up the question of whether or not you trade a popular player who has contributed and what you can expect from fans when you do exactly that.
In baseball, nostalgia and sentimentality end when a player stops being productive. No matter who you are, you're gone if you can't produce. I'm not aware of the inability of Kevin Youkilis to produce for Boston. Are they happy to see him go? Or are they howling for blood?