I tried to send this POS to the minors and I got this,
You are attempting to outright Yorvit Ortiz to the minor leagues. He has the choice of becoming a free agent instead of accepting the assignment. We asked the player what he would do and he responded that he would elect to become a free agent. You may either keep him on your roster or release him.
Do I still have to pay him if he elects to become a free agent?

Yep.   All but the pro-rated minimum salary each year for the duration of the contract if he's picked up by someone else.   Full salary if he isn't.

Yeah, you don't want to do that.

I saw this message once before, in my very first season, but the player accepted his demotion.  At what point does the player have the option of becoming a free agent rather than being demoted???

HA!  I remembered the work-around.   Designate him with waivers if you can.    He'll accept the demotion then.

Anyone I have ever designated has always accepted the demotion. Has there ever been an instance where the player ever opted for FA? What was the results if it has ever happened?

i've had several guys decide they wanted to be free agents instead of being sent to the minors.

If my agent told me, "sergei wants you to go down," I'd hit the road, too.

Straight to sergie's house? 

Good one, Mike!