Conceding that confidence could play a part, he said that a lack of cohesion or his decision to change things around in search of the best formula could also be contributing but while assuming some of the responsibility, he said players had to look in the mirror as well.
“At some point the responsibility comes to the players, to take those opportunities that are provided for them,” said Postecoglou. “At the moment they are just not doing that.
“I have felt that in our three competitive games. It is the area we need to improve the most on. Defensively we are being put under pressure for any period of time but if you keep the opposition in the game then there is always a possibility that, from a set piece or a counter attack, they can hurt you.”
A third competitive game without a victory, the Celtic boss had thrown Carl Starfelt into the starting line up in a bid to strengthen the defence but within eight minutes, his side were trailing last season’s Championship winners.
A goal from Anthony Ralston levelled things in the 54th minute but lacking a clinical edge, and denied by former goalkeeper Craig Gordon, they were unable to add to their tally, leaving the door open for Hearts’ John Souttar to do what they couldn’t and grab a late winner.
“It is disappointing and I am going to have to look at it again,” said Postecoglou. “It is a set-piece – we should be organised and we knew that would be a major threat from them and we had dealt with it well all night. But you keep the opposition in the game if you don’t take control of those areas.
“The first 5-10 mins were chaotic, which we expected when we conceded, but then we grew into the game. But in the final third our play wasn’t great. We got into some good areas with very little reward but when we scored I thought we would go on from there. We had some opportunities but obviously it was disappointing to concede late.”