Erik Sviatchenko has long left Celtic but Celtic has never really left him.

The FC Midtjylland defender and his son, William, watched Celtic lift a quadruple Treble via their Celtic TV subscription while the four-year-old danced around in celebration sporting the colours of his father’s former club.

A WhatsApp group keeps Sviatchenko in touch with Kris Ajer, who dispatched the winning penalty, as well as Ryan Christie and former Parkhead midfielder Stuart Armstrong. And while Sviatchenko felt it was important that Celtic enjoyed the moment as they sealed a quadruple Treble he was also keen to stress that it can become particularly significant if it is the catalyst for a league revival.

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“I think there has been a lot of tension around the club because of what is going on this season,” said the FC Midtjylland defender who recently captained his side to a draw against Liverpool in the Champions League.

“The pressure to win the quadruple treble has been there as has the desire to go and win 10-in-a-row. I think that having now delivered another treble it does relieve some of the pressure on the players.

“They have not become a bad team overnight but they do look like they have lost some confidence. This can help them relax a bit and take some of the tension out.”

There has not been much cause for singing and dancing so far this season at Celtic.

The weekend enabled Rangers to stretch their league lead to 16 points with Celtic now facing three games in hand to make up some of that ground. It remains a fairly big ask.

On the evidence of Sunday’s display at Hampden the question marks over the defensive issues prevail. The January window may offer an opportunity to address those deficiencies but it would be remiss to overlook the mental frailty too that seems to beset Celtic as soon as they concede a goal.

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And while time will put Sunday’s achievement in a particular context – it is difficult to see another team achieve what Celtic have – it will not put enough credit in the bank to dispel any of the angst that has built up around this season’s league title charge.

“It must be difficult for the players just now,” said Sviatchenko. “There are big emotions around Celtic and the support demand that the team are winning.

“I see it is a strong thing for Scottish football that you have a strong Rangers team who are capable of challenging for the title. But I still think that it is too early to write Celtic off.

“They have a team full of experience and although there has been some difficult weeks recently it is not over yet. They still have time.”

Ajer has been one of those who have come under scrutiny this term at Celtic.

Having been linked with a move to AC Milan, the 22-year-old Norwegian has had the finger pointed at him by a support who suggested he was one of the dissenting voices within the dressing rom. For Sviatchenko, who took the player under his wing in the early stages of his Celtic career, his celebration when he scored the winning penalty showed just what the occasion meant to him.

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“He is such a big player that as he raced away I think his celebration looked pretty iconic,” he said.

“He showed great composure with the penalty and I am so pleased for him. It was such a special moment and you could see just how much it meant to him – and to all the players.

“He has grown into such a big player for Celtic and he really handled that pressure.

“Kris has been rising to the occasion all the time so I was not surprised to see him step up and take on that responsibility.”

Ajer has been moved out right in recent weeks, a switch in organisation that has enabled him to get on the ball more but for Sviatchenko his attributes all point to a career as a centre-half.

“For me he is a defender,” he said. “He has all the attributes of the very top players in that position because of his ability to carry the ball.

“I am sure he will have enjoyed having a little more freedom recently and also there is not quite the same pressure in a wider position. If you lose the ball there is still a chance to redeem the situation or expect that one of the defenders can help you out.

“If you are one of two central defenders then there is more pressure on you. I still think that as he matures into the game that will be in his best position and you can already see that a lot of teams in Europe have taken note of what he has done.

“It is those raw attributes he has that make him so attractive to teams. But he also has the mentality too, as we have seen on Sunday at Hampden.

“Because of his physical size then he can protect the ball well. It can be hard to get near him just because physically he is so imposing.

“It has been a tough season for him so far but Sunday can be a big moment for him and for the team.”

The one area, however, where Sviatchenko has challenged Ajer to improve upon his return in front of goal.

“I joke with him that I am two heads smaller than him and I have a better record from set-pieces,” said the defender who captained Midtjylland to a draw against Liverpool in the Champions League earlier this month.

“If he can add that to his game then it will be something else for him to have. I have spoken to John Kennedy about it and we both think he can chip in with a few goals.”