As for what I'd do, I'd rotate starts between the following 6 players if Cabrera comes back strong: Boyd, Gausman, Holmes, Imanaga, Peterson, Cabrera. Keep Rea around for mop up long-relief duty, put Assad in the minors since he has options.
For the last 6 in the pen, you keep Webb and Rollison because they've been nails, Palencia could be the closer or setup guy, and Zeferjahn is a good complement to Palencia, and that should effectively cover the last 3 innings of any game in the postseason. Past that, if Brown and Steele are healthy and can be effective, that's the last 2 spots. If not, keep them on the 60-day DL and figure out your best 2 out of Maton, Thornton, Ferguson, Civale, Milner, Miller and Thielbar.