Must Keep: Wikelman, Perales (guys I would put on the 40 man immediately after the season)
Should Keep: Bonaci, Drohan, Gambrell (guys I have to fit in prior to the Rule 5)
Bubble Keep: Liu, Castro, Bastardo, Fernandez, Hagenman, Scott (guys I would like to keep, but am going to leave unprotected even though some may be picked)
Liu should be pushed to the pen as his arm will play up there and he could reduce his pitch selection. Castro is looking like a really solid prospect right now and a team could jump on him, but it's more likely he goes unselected. Bastardo and Fernandez are bullpen arms the typically get scooped up via Rule 5. Neither of those two have late inning upside so I wouldn't bother protecting. Hagenman was a deadline acquisition for Bloom this year, so there's a good chance he is put onto the 40 man (I wouldn't protect for the same reason as Bastardo/Fernandez). Scott is terrible at throwing out runners and his pop time would be the worst in MLB. He'd be useful as a mix and match guy (C/1B/LF), but you don't want him catching too often and his bat still needs to play up. I could see a team selecting Scott for sure.
There are some other relievers in the org that could also get selected in Rule 5 like Zeferjahn, Politi, Shugart and BELL. The only guy from that group that I'd personally regret losing would be Brock Bell as he just got back from an extensive injury rehab and is still a little bit of a mystery, but probably should be up in the Portland bullpen right now.