He told City's website: "There has to be a mentality and a mindset that we're not going to get beaten.
"Every time you go out on the pitch you make a point of taking something out of the game in a positive way. At the moment we are struggling in that respect and we need to be better and really dig in on occasions and see games out to a positive conclusion.
"We have to take things from every game we play if we want to challenge. We need to get better in that respect but sometimes circumstances arise and it's not something that I like to criticise because you get nowhere by doing it, but the referee had an average performance, if I can say that and that's putting it mildly.
"There were quite a few occasions we he made decisions that left both sets of supporters and teams questioning what decision he had made. In the end we've lost a game that we had chances to win.
"That's where we are but we want to be a successful side on all fronts.
"We've got a campaign in Europe that we're excited about but the Premier League is our bread and butter. So we have to step up to the mark and make sure that we perform at a consistent level.
"At the moment we're a little bit in and out and that's a frustration for us because we know we've got talented players in the team and when we play well, as we've seen, we can play some fantastic stuff."