Gay is cancerous at the very least in required touches, a black hole if you will.
But memphis strengths are in the post with Zbo and Gasol. I suspect Gay takes too much away from that, because of what Gay is (All star and a pretty good player).
So there are not enough touches to go around.
BUT, Gay is still the best SF option they have. Any coach worth a damn would figure out how to ice that drama, if it existed.
This does not explain why they are shopping ZBo too, which may be a lie.
The likeliest scnerario is the Memphis ownership cannot justify paying the tax if they are not top tier contenders. I think this is bullshit, they are a force and a fourth seed. Can you imagine if Cuban had this current predicament? He'd probably figure out a way to get someone like Kidd on the roster stat.