Starting with the 38 they have now on active roster:
4 are free agents (Rojas, Taylor, Civale, Alexander)
3 get added back on from 60 day IL (Thorpe, Bush, Berroa)
3 seem like obvious drops (Noda, White, Shuster) of which later 2 are out of minor league options anyway
That gets you to 34 in offseason and the 6 spots for rule 5 protection