RONNY DEILA, the Celtic manager, has defended the standard of refereeing in Scottish football but also called for officials to explain their actions as happens in his native Norway.

Deila was speaking at the end of a week dominated by discussion over the non-award of a penalty to Celtic in last weekend's William Hill Scottish Cup semi-final defeat following a handball by Inverness Caledonian Thistle's Josh Meekings, the subsequent notice of complaint and offer of a one-match ban to Meekings, and his successful appeal that frees him to play in the final. Celtic, frustrated by a lack of clarity on the matter, also wrote a letter to the Scottish Football Association looking for an explanation as to how referee Steven McLean and his assistants all missed the handball.

Deila, in his first season in Scottish football, has been generally positive about referees here and was not of a mind to change his viewpoint following this incident. He felt, however, that it would help eliminate confusion if referees were to appear before the media after a match in the same way that he and his players must do.

"I think the referees have been good," he said. "I haven't changed my mind on that. You see mistakes all over Europe and I think the referees here have been good, I have no problems with that.

"But when my team has a bad performance, I have to stand in front of newspapers and everybody else. I can't understand what the problem would be with the referees doing it as well.

"They could say, "I made a bad mistake, I'm so sorry, I'm irritated at myself, I should have done it better, I should learn from this". What could you say after that? But when you don't get an answer and have to write [letters], you never get finished with it.

"It would be good for them, too. We all know refs will make mistakes in the future and do good and bad things. We will do the same, but just to be open and honest gets you much more respect. You have to be able to handle it through good times and bad times.

"More and more in Norway, the referees go to speak to the media after the match. They get banned as well. They get told they have to go down to the first division for a couple of matches or have a week off and then come back again. That is made public."

Deila, whose side faces Dundee United tomorrow looking to move a step closer to a fourth consecutive title, revealed he has already begun the process of looking to improve his squad in the summer. Following the success of Stuart Armstrong and Gary Mackay-Steven, his preference where possible will be to sign more Scots.

"First we will to see if there is someone here in the country or who is a Scottish player who can come back from being abroad," he revealed.

"This is important because players often want to come home and they know what Celtic and Scottish football is all about."

Charlie Mulgrew, absent since December with a knee injury, is edging closer to full fitness, with Deila revealing he could still figure in Scotland's vital Euro 2016 clash against the Republic of Ireland in June.

"Charlie is getting closer and closer now. He is in full training but at 95 percent. We knew when he got the injury back again he would be a long time. But now he's very positive and hopefully he will get a couple of games before the end of the season. Maybe then he will also be available for Scotland."