Minor League Baseball Dl

What happens when a player refuses a minor league assignment?
I hear of players who refuse minor league assignments, however; I am confused as to what happens to them if they do so. Does this mean that they simply no longer are with the team? Or do they remain on the team? Do they place them on the DL?
Do they sign with another team?
If they are no longer with their team, I would think it could possibly be the end of their baseball careers or at least be sometime before they resign.
Usually he is just released outright so that he may pursue any other team that
may show interest in him.
Breaking News – Raul Ibanez Placed on DL, Manny Ramirez to Single-A, and Pudge Breaks Record