Orelvis is only going to come up when the plan is for him to start everyday at 2nd base. Whether that's a result of Biggio, and Schneider struggling, or Kiermaier struggling and one of them being OF more often, or injuries to one or both of them, or Orelvis having a 1.300 OPS when June gets here essentially forcing his way up. If he then comes up and struggles or the plan shifts they can send him back down if he loses playing time. He needs to be playing wherever that is. He's our best chance at a star bat long term.
Barger I'm not sure. Obviously you want him playing too, but his development may not be vital enough where you're completely against him coming up at some point and only starting half of the time.
Horwitz is the bench player I think if they want to call someone up to exclusively be a spare part for now.
Vogelbach is the only piece they should be willing to just ditch at any point. Everyone else is playing well enough, get paid enough or has enough team control you don't want to punt them off the roster. I don't care if IKF, or Kiermaier, or Biggio sits on the bench for a while. Even Schneider and Clement can do that too if one of the other guys forces their way on the team. But none of those 5 are getting optioned or DFA'd anytime soon.