I think the chatter pregame mostly centred around the concern that the starting 11 meritocracy wasn't exactly fair nor was there much use of the squad. This is one of those 'can't believe you're moaning' posts but if you don't highlight the problems when you're winning you have no right to complain when you lose.
Per Mertesacker was rightly pulled from the starting line up, Wenger said it was due to the amount of games he's played which has to be true. It's also down to a severe lack of form that most likely correlates with the latter point. The manager also pulled #WELBZ and put Chambo in his place (who was pretty poor to be fair).