Ronny Deila has said that he is irritated by Celtic's inability to score during their 0-0 draw against Hearts.
Celtic dominated the match but were unable to take any of their chances and remain four points behind league leaders Aberdeen.
"I think disappointed is the wrong word. I'm irritated because our performance today was good, and you can't create more than we did in the first half," Deila told the club's official website.
"I don't think they had a chance in the whole game, apart from maybe at the end when we got the red card, and that wasn't really a goal chance.
"We probably had about 70 per cent possession and created a lot of chances, but we could talk about that all day long. It's about scoring goals and we didn't do that today."
Celtic took 24 shots to Hearts five and kept 64% of the possession throughout the match.