You're right to a point. It's over $2 mill we'd create in savings this year. We'd lose the roughly $19 mill next year. But we also have to pay him the $19 mill this year. That doesn't disappear.
Now, what kind of quality replacement can you find for roughly $2 mill to take his place, even if he only played part time?
Reality is, you don't trade him this year. If you can, during the upcoming offseason, fine. At least you might get a cup of coffee for him. Now? You won't get anything. He's damaged property. He needs to heal enough and play enough, to at least make him trade bait.
You don't trade him this year. It makes absolutely no sense, and those "writers" who purport to be experts advocating it are insane.
But, that's just my opinion. Who am I to rain on anyone's Alice in Wonderland Parade.