Celtic manager Ronny Deila expressed his frustration at his shot-shy side after they were held to a goalless draw by Hearts on Saturday.

The Hoops reduced the deficit at the top of the Scottish Premiership to four points but Deila was left fuming after Celtic failed to take full advantage of leaders Aberdeen's 2-1 defeat to Inverness Caledonian Thistle.

The Glasgow giants, who last week routed Dundee 6-0 at Celtic Park, spurned numerous chances and came up against some resolute defending from Hearts, who ended a 10-game losing streak against the Hoops.

"Disappointed is the wrong word; I'm irritated as our performance today was good," Deila said.

"You can't create more than we did in the first half. I don't think they had a goal chance in the whole game.

"The team kept Hearts under pressure for 90 minutes and in the end they just parked the bus inside the 18 yard box and that is hard.

"Defensively we kept them under pressure the whole time. I'm sure we had about 70 per cent possession and we created chances.

"You need more movements in the box when you get crosses. There were too many who wanted to score the goal themselves and standing behind people instead of trying to drag people away.

"We should have created more from our crosses because I think we had 30 crosses in the second half.

"But we can talk about that all day long; it's about scoring goals and we didn't do that today.

"I have to say as a manager that I'm pleased with the performance and that we created chances, but very irritated that we didn't get more chances out of all the crosses we had in the second half.

"If we had got one then there would have been more spaces and I think we would have got even more."

Top scorer Leigh Griffiths had returned to lead the line for Celtic as one of six changes Deila made from the midweek League Cup win over Raith Rovers.

But the striker, who had netted in six consecutive league matches going into the game, fluffed a number of opportunities in an exasperating afternoon.

"I think as a striker you won't get any more clear cut chances. Leigh had four or five alone but he has scored in every game for a long period now," his manager said.

"Everyone has ups and downs during a season but today I'm sure he is irritated at himself that he didn't score."

Celtic host Fenerbahce on Thursday night in their Europa League clash and Deila said his side will have to be more clinical if they are to pick up any points against the Turkish giants.

"We will not be OK if we play like that on Thursday as we didn't score a goal. It's going to be a tough game," the Hoops boss said.

"There are a lot of things we did today that are going to be good enough on Thursday but we need to be more effective.

"In Europe you get punished harder and you need to punish them when you get the chance."

The Celtic manager confirmed midfielder Charlie Mulgrew will miss out on the match through injury but said Stuart Armstrong could feature after returning to training.