Celtic manager Ange Postecoglou is targeting an improved performance as the champions bid to back up their 9-0 win over Dundee United when they host Rangers.Postecoglou claimed there would be "zero" significance in going five points clear at the top of the cinch Premiership six matches in, and highlighted the fact that he lost his first derby meeting before winning the league after being asked about the importance of winning the opening clash with their city rivals this season.Instead of being caught up in the hype, the former Australia head coach is looking for a continuation of the progress he has seen in his team in the early part of the campaign.Celtic have scored 25 goals in six matches and Postecoglou was able to make nine changes for Wednesday's Premier Sports Cup tie against Ross County and still mastermind a 4-1 win."We have grown into the season and that’s what we are looking for – an improvement in our performance, an improvement in how we do things, and play our football, and overcome whatever challenge we have on Saturday," said Postecoglou."That gets you three points and you move on to the next challenge."Our incentive is to keep performing to the levels we have and keep improving on them."After winning his first two battles with Giovanni van Bronckhorst, Postecoglou suffered defeat against the Dutchman’s side in the Scottish Cup semi-finals and the final meeting in the league last season ended in a Parkhead draw.But the Celtic boss stressed that the players would define the outcome."I know it’s fascinating for other people but I have never really been into manager versus manager – we don’t play the games."You assess each team as a separate entity and what you find is they always evolve.