RONNY DEILA, the Celtic manager, felt that justice had been served after defender Virgil van Dijk was cleared to face Dundee United in Sunday's League Cup final at Hampden.

On a busy afternoon for the Scottish Football Association's disciplinary panel, the Dutchman had the red card shown to him in last weekend's William Hill Scottish Cup quarter-final at Tannadice rescinded, as did United's Paul Paton who had been sent off in a case of mistaken identity. Nadir Ciftci also escaped punishment, the tribunal delivering a "not proven" verdict to the charge that the Turk had kicked Scott Brown in the head during the same match. Ciftci, however, will still miss the final due to picking up two bookings earlier in the competition.

With Adam Matthews and Charlie Mulgrew both still injured, the additional loss of van Dijk would have left manager Ronny Deila short of defensive options He was a relieved man, then, when word reached him that van Dijk's appeal had been upheld.

"It was the right decision," said the Norwegian. "I don't think it was a red card and I'm happy that he can play in the final. It would have been harsh and finals should have the best players in them. I'm happy for Virgil. It is very good news for the team as well. He is an important player for us. He was disappointed with the red card against Inter Milan and then he got another one. He said to me in November, after getting a yellow card, that he'd never had one before and now he's had two reds. But we've had the right decision now."

Deila felt that football would eventually follow other sports by introducing video technology to help match officials reach the correct decisions.

"It's a tough job to be a referee," he added. "Sometimes they have a bad day as well. If we are using cameras we have to be consistent. If people can make mistakes, I can live with it. [Is it time for a video referee like in rugby or tennis?] That's a very hard discussion.

"But I think so, that could be good for the big situations because, again, there is so much at stake there. Money, training, glory, fans - everything. And it should be right. You see goal-line technology has come now and I think that's positive. They can have a chance to go off and say if they got it right or not. I think that can only be positive for everyone - because everyone wants the best team to win. I think football will get there in a few years."

Given the feistiness of last Sunday's match, the expectation is that the final will be just as competitive. Deila, though, called for cool heads.

"Sometimes [referees] are too quick to give cards," he added. "But we have to be disciplined. We have to think and not do stupid things. Stay or your feet and nothing will happen. It was the same against Rangers [in the semi-final]. If you lose your discipline there and get a red card you can lose the game. I think we have been disciplined."

His opposite number, Jackie McNamara, made a similar plea. "I think that's key to it," he added. "It shouldn't come into play at all what happened last Sunday. I'll make sure the players understand the importance of discipline. We have to be committed, we have to compete but first and foremost we have to make sure we keep our cool."

With Deila again questioning why United's Aidan Connolly hadn't been cited for a perceived dive in last weekend's tie, McNamara had a veiled dig at Celtic and their persistent protests.

"From our point of view, we have kept our silence and our focus on Sunday," he added. "We haven't mentioned anything about wanting anyone suspended or this guy has done this or that. We're focused on our own team. The last thing I'd want is any of my players to speak out about the opposition and what not when it's been dealt with by the authorities. I'm pleased they haven't. That might have taken their focus away from the game. It shouldn't."

Deila is eagerly anticipating his first cup final in Scottish football but revealed the build-up at Celtic - regularly accustomed to gracing such settings - has been rather low-key than when Stromsgodset, his former club, lifted the Norwegian Cup in 2010.

"I am very calm. Maybe too much. Hopefully it will come on Sunday but we have so many big matches you get used to it. I have seen crazy things at the cup final. It is big in Norway, there is only one cup and, like the FA Cup, it's the last game of the season and is always sold out. There are things like, "who is going to sit beside the King?" That's how it is with small clubs."