BURNLEY manager Steve Cotterill believes his ever-improving back four will be key to maintaining the good start to the season.

The Clarets head to second-placed Bristol City tomorrow with a record of just one defeat from their opening seven games.

While goalscorers Alan Mahon, Andy Gray, Robbie Blake and Chris McCann earned the plaudits in picking up maximum points from the last two trips to Colchester United and Sheffield Wednesday respectively, Cotterill believes growing consistency among his defence has been just as crucial.

And he insisted that their first clean sheet of the campaign in midweek was reward for their efforts to gain an early understanding as a unit.

"The back four, I thought were excellent (at Sheffield Wednesday), he said.

"Even when they didn't touch the ball, where they were stood, I thought their positioning and looking after each other's backs the other night was excellent.

"They don't have to kick-on any more. If they can do, fantastic. But if they kept it like that for the next 40-odd games I'd be delighted.

"I always think trying to get that first clean sheet in the opening week is important.

"Your first win, your first goal and your first clean sheet - if you can get that all in the first week of the season, that's what you're trying to aim for.

"We try to aim for those things every season. The clean sheet has been longer coming, but I think that has definitely been down to the changes in personnel.

"We've changed the goalkeeper, then from the first day we lost Wayne Thomas, and then for the next game David Unsworth came in, then for the next game Clarke Carlisle came in. We've changed the left back to Stephen Jordan.

"The first time they would have met each other is when the captain introduced them in the dressing room.

"They're finding a lot out about each other, and the good thing about it at the moment is that there is a good, healthy, competitive spirit amongst them, without going over the line.

"The longer we can keep that and the competition, the better it will be for everybody."

Cotterill added: "They'll understand each other the more they play.

"There are partnerships all round. You're looking for your back four to have a partnership, you're looking for your fullback and your wide man to have a partnership, your central midfielders to have a partnership, strikers to have a partnership.

"The more of those good partnerships you can get round your team, the better your team will be."