Aubameyang and Odegaard, who is on loan from Real Madrid, missed training Tuesday because of illness and an ankle injury respectively.
Arsenal were due to train Wednesday before travelling to the Czech Republic with the tie all-square at 1-1 and Arteta, asked if the duo would take part in the session, told reporters: "It depends how they wake up. (On Tuesday) none of them could train. Hopefully (on Wednesday) it is a sunnier day so maybe it is better.
"I don't know, we have to see how they are. We still have a couple of other ones as well from the last few days, so we'll have to see how everybody is and after training how they react for (Thursday's) game."