I think the 2021 rotation probably contains Eovaldi, Erod (hopefully), Perez, Hernandez and a free agent. Godley might be able to hang on as a depth starter or ERod insurance, but it's a bit early to tell. So if they add, say, Bauer to that mix, it looks a lot more resepctable. Especially when Sale comes back.
Now the bullpen is anybody's guess. Walden, Taylor, and Brice probably all return, if for no other reason than there is no one else left. And maybe Godley if he is not in the rotation. So hopefully they get something good when they trade Workman, Barnes and possibly Hembree and either Dalbec or Chavis...