The team will try to trade LHP Andrew Miller.
This isn't a bad move for anyone concerned. BGA just hasn't gotten it done in his time with the Marlins. Being a first round pick, with lots of undeveloped talent, there is always a club out there that thinks: if we can just get him with our pitching coaches we can tap that talent. And maybe they can. A change of scenery might also help the lad.
Miller is out of options so it is best to see what the Marlins can get for him now. Because if they don't try to trade him, eventually he will be DFA'd, and he will, some team will just claim him off waivers and he will be gone. BGA might not have a lot of value at this point, but he is surely worth something.
Andrew by all accounts is a good guy, and while I was once told there is no market for good guys, there is a market for lefties and he is definitely one.