You would have to think after the performance of Palacios, he would be a certainty to get into the starting lineup as one of the midfield 3. Issue is Aranguiz is undroppable given his importance while Demirbey has been good I think at the start.
@Zehner do you think Palacios will get more playing time?
I hope so. To be honest I think your assessment of Demirbay isn't accurate. He's probably the most criticized player among Leverkusen fans alongside Bellarabi, currently, and I think that's more than fair. In his last games he was very, very wasteful and at times finished the match with ~70% passing accuracy without offering anything attacking wise either. So far I'm really disappointed with his signing.
Think a midfield consisting of Aranguiz, Palacios and Wirtz/Paulinho would be our best formation at the moment. But it seems like Palacios is actually even behind Baumgartlinger in the pecking order which is a shame. Hope the last game made Bosz change his mind.