He can't seem to play without Laca recently. He's missing easy chances and we need to create more for him. If Emery won't play him and Laca from the start, then Laca should start.
Laca is clearly creating space for him and taking defenders off his back. It feels similar to the Lewandowski/Muller partnership at Bayern: Although the latter is in horrible form, the former is clearly better when Muller occupies defenders for him by basically just being there.
At Dortmund Auba was playing a lone 9, but he had decidedly more dangerous attacking players who were driving at goal themselves behind him, which got defenders off his back. In this slow moving, ball shifting and toothless Arsenal he's under constant surveillance by defenders. It's bogus to play him that way; if it's only one striker for now then it should be Laca the way this team is playing right now. But the way to go should actually be to have both on the pitch and get us to play faster, more direct and more penetrative football.