Maybe not as remote as people think.
Giles - lock
Tepera - lock
Norris - lock
Biagini - 1 option
Phelps - won't be ready
Axford - not a lock
Mayza - 2 options
Paulino - 1 option
Barnes - not on 40
Guerra - not on 40
So right now they could break with Axford, two of Mayza/Biagini/Paulino, and Luciano.
There's really nothing to gain by returning Luciano. And there's nothing to lose by sending Mayza to Buffalo.