Actually it is. They have less leverage because it looks like they are being pressured to trade him. I think the bigger hit on his value though is his contract. If you take him on now, you basically pay $20 million for a $16 million cap hit. The longer it takes to trade him the closer that figure gets to paying $14 million real dollars for an $8 million cap hit. That's like paying a luxury tax to get Asik. Now look at how so many teams seem alergic to paying taxes and you see the number of potential buyers shrink. Fewer buyers = lower price. It's definitely in Houston's interest to sell sooner rather than later on Asik. No reasonable offers refused.
Unless the team is already close to paying the tax. In that case, Asik's contract is actually a cost saver because his value may exceed the cap hit, and the extra salary is less than the tax payment. Plus, you may still be able to shell out some of that case AND get the tax distribution.
It's a fun contract.