man, I don't know how many times I need to explain this. Ok, so most people are saying.. why would you want to pump a guy up, and then trade that guy, because if you're able to pump a guy up, then you might as well stick with the guy, because he's shown he can "be that guy" so to speak, during the period that you're pumping up his stats.
If that's what most of you are implying, then this is my take...
As a GM, you need to make decisions about your players, and the future of your team. If you decide that ulimately, DeMarcus is more trouble than he's worth, and he will never be that guy that you need him to be (both on the court and off the court and physically and mentally), then you have to stick to your convictions about that, and say, you know what... DeMarcus isn't the guy that we need on this team. Despite his talent level and everything else, he's ultimately a "net negative". Ok, so if you've come to that conclusion, and you've internally made that decision, what you DON'T do, is broadcast this information around the league, and let everybody know that you've decided to "move" DeMarcus. You have to keep that as secret as possible, don't tell a damn soul, and in fact, do the complete opposite. Praise DeMarcus at every turn, back him up at every turn, give him maximum playing time, run the offense thru him, pump up his stats as much as possible and then out of nowhere, you trade him.
The idea being, that you have this asset, an asset that you personally see as a liability, and you do everything in your power to try to hide the fact that you see that asset as a liability, because you are hoping to sell that asset for maximum value.
The decision has already been made. You've already decided that he's not in your future plans. Just cause he might start putting up some huge games, that shouldn't change your mind. All that should do, is make you smile, because you know you're going to get more in return when you are able to finally trade him away. I'm personally of the belief that people really don't change all that much. DeMarcus is what he is. He might calm down a bit over time ( a LONG time), but he's ultimately going to be a net negative wherever he goes. Get rid of him. But don't get rid of him in a firesale. Pump his value up, and then dump him like a bad habit.