Sydney FC are flying at the top of the A-League ladder but coach Steve Corica is in the pursuit of perfection in the form of more clean sheets.
After Saturday night's 2-1 win over Adelaide at Netstrata Jubilee Stadium, the Sky Blues notched up their 10th victory of the season, but leaked one too many goals for Corica's liking.
So far this season they have claimed just two clean sheets against Western United and Central Coast Mariners.
Saturday night's blemish was a goal from Riley McGree off a set piece from a free kick - the second week in a row they have conceded in the same fashion.
"Two in two weeks is a bit of a problem. It's something that we need to look at to make sure it doesn't happen again next week," Corica said after the game.
"It's not great when you concede on set pieces because I thought other than that we looked very strong defensively and it's disappointing.
"There's obviously still stuff we can work on and get better and that's the plan."
However, after 12 straight wins at their Kogarah home ground, and 10 consecutive home wins across three venues, Corica is hardly frustrated with the defensive form of his team.
"We don't want to stand still, we want to improve and that's part of it," he said.
"Clean sheets are a big way of obviously winning games but also great for confidence for the backline, for the goalkeeper and everyone involved."
"(It doesn't) frustrate me, not at all because we have the quality up front to score goals.
"We go into every game to keep a clean sheet, to work hard defensively and try not to concede but the opponent obviously is a real challenge sometimes and they deserve the goal, it was a good set piece by them."