I prefer to approach it as "Out of Our Starters, who is the most "Possible" trade asset. Excluding 1 year contract, expiring...Hickson from the equation and I would answer Wesley Matthews.
Don't mistake this statement as in any way shape or form meaning I advocate for trading him, I do not. I think he is severely underrated. He's probably our best individual defender, and he has a warriors mentality. But it becomes pretty simple, baring a disaster The Blazers are not trading Aldridge, Batum or Lillard....by default that leaves Wesley.
There are a lot of scenario's where it could work. Move Batum to 2 guard? Replace your SF? Leave Batum at SF....find a replacement 2 guard?
If you think of it as a "JENGA" tower, and you are forced to remove one piece from the base? Wesley arguably is the piece you could possibly remove without destroying everything. It would depend entirely on what you were getting for him, and what you believe you may already have.
That being said, while Aldridge, Batum and Lillard get much of the spotlight, Wesley just quietly does the right thing. Defends, scores and hit's the big shots. His commentary makes me believe he is a good type of person to have in the locker room. Unless the gain was undeniable? I certainly wouldn't sacrifice Wesley.
The Blazers are in the slow, somewhat arduous stage of rebuilding their depth and asset base. Right now, The Blazers simply do not have the depth to make a major trade, unless you want to digress this rebuild, to a total ground up rebuild, which I do not believe The Blazers want to do.