Roberto Mancini's men currently lie six points behind city rivals Manchester United - and rumours of divisions within the squad have spread since the 3-2 derby defeat on 9 December.
But Milner said: "Nothing changes really. It's been like that since I've been at the club - players are not happy, players are arguing. We'll just continue what we do best and that's getting out on the field and getting three points.
"We need to keep improving as a team. I think the best is yet to come this season and let's hope we can keep moving forward.
"When you're at the top and you're champions, people want to knock you off that pedestal and they'll try anything whether it's on the field or off the field. They are things you learn to deal with.
"It definitely brings you closer together when everyone outside is against you. You have that siege mentality and put that to good use."
After coolly outclassing Newcastle 3-1 at St James' Park at the weekend, the champions welcome struggling new boys Reading to the Etihad Stadium next up on Saturday.
Don't miss any live and exclusive football coverage this festive season. Click here to visit Sky Sports' Festive Calendar