Even if Arteta fields his third eleven those player's are highly spirited they have no chill at the moment as you can see the desire in them wanting to win game's. PSV are good side's, very good with counter attack's if they don't handle the game well, PSV will capitalized on that and score goals. Former Man United player van Nistelrooy will face his old rival's can he handle the pressure when the Europa League resumes nest week
Okay maybe not that much 
I get that Arsenal is doing awesome this year, and they are quite hyped, but I would say maybe a few players missing would be the best they could do.Their biggest advantage is that other teams in the premier league that are their rivals for the title plays in UCL and care about UCL a lot more, City would want to win UCL more than winning EPL for example, whereas Arsenal would be happy to get Europa, but would prefer to get EPL instead, and that is why they will play their best 11 on EPL, whereas City would play the best on UCL, and this is why we could maybe see a shocking loss from Arsenal on Europa time to time, maybe even eliminated.