Ziegler is a good RP but is also a FA I believe. Kimbrel has done a fairly good job, Buchholz has looked better with the bullpen work, Ross is a valuable BP asset, Barnes just isn't getting it done despite the good velocity, Tazawa has been used an awful lot and then was injured (maybe his career is on the downside but he deserve much credit for all the past work he has done), Abad in my opinion, has very good stuff and is acclimatizing himself to the new position (I would definitely keep him).
Do we have enough relief pitching to get to the Playoffs? It hasn't looked good and in combination with JF's reluctance to pull pitchers until the damage is done further harms our chances.