Notwithstanding the above, I expect that there will be trades between now and November - trades of some of the guys who would otherwise be gone after 2017 - and that some of what comes back in trade will be players that have to be on the winter 40-man roster, so we will likely be looking at fewer than 12 available roster spots.
The following probably misses somebody, but this is the list I have of players who become first-time eligible for the Rule 5 draft this winter (I've bolded the ones I consider at risk, and might care about):
Antequera, Jose
Arano, Victor
Armas, Gustavo
Brown, Aaron
Cabrera, Ismael
Campbell, Derek
Carrasco, Luis
Crawford, J.P.
Cumana, Grenny
Davis, Austin
DeNato, Joey
Fisher, Joel
Garcia, Enmanuel
Gonzalez, Reiwal
Hernandez, Jan
Hockenberry, Matt
Hoskins, Rhys
Kilome, Franklyn
Leibrandt, Brandon
Marrero, Emmanuel
Mateo, Gregorix
Melendez, Orestes
Nunez, Anderson
Paulino, Felix
Richy, John
Rivero, Alexis
Salazar, Carlos
Sandberg, Cord
Stankiewicz, Drew
Taveras, Jose
Tomscha, Damek
Viza, Tyler
There are also some guys who have been exposed to the Rule 5 in the past who might attract some interest (but some of these guys, at least, are by definition marginal):
Grullon, Deivi
Milner, Hoby
Murray, Colton
Perkins, Cameron
Pullin, Andrew
Tocci, Carlos
Walding, Mitch
I'm not seeing a major problem here - certainly not a problem that would lead a GM to expose a J.P. Crawford to the Rule 5 draft.