Humphries.
Prior to last season he averaged 14 and 11 whole sorting a pretty good percentage from the field too. He's a nice guy, but I don't see Bass ever averaging those numbers under any circumstances, in any lineup. Bass seems like he can either score or rebound/defend, but he seems completely incapable of doing both in the same game.
Also Bass is listed at 6'8" but it's actually 6'7" with shoes and wat undersized for the NBA PF spot. Humphries is listed at 6'9" but actually stands 6'10" in shoes, which is much better. Bs gets by with his muscle, but Humphries is at least as beefy as he is.
Humphreys + Sully would make one hell of a rebounding font court, while pairing him with a shooter like Bass or Olynyk could have us force him to play, inside more. From what I understand he is a decently capable scorer inside when he wants to.
I live bass as a player but I don't se where he fits a rebuilding team like boson now. He's much more valuable I think as a solid bet on a playoff team.