Well, yes. And I would also seriously consider trading of them (I'd trade Zeller because he has the least upside). I really don't see room for all 3 of them in the rotation with Johnson and Lee here, and that's not even counting getting Mickey or Jerbenko any time (or playing Crowder at the 4 in small ball lineups).
Now I wouldn't give anyone away. But if someone wanted to give us something worthwhile for one of them, I'd jump on it, because whoever rides the pine will just see his value go down as the season progresses (and that's another reason I'd move Zeller--I think we'd be selling high on him, whereas with Olynyk and Sully I think we'd be selling low at this point).