As Ronny Deila walked out of Hampden on Sunday evening, an observant soul might have invited him to leave his belt and shoe laces behind.

The quiet, resigned demeanour of the Norwegian told its own story as the defeat to Rangers stripped him of a final shred of credibility.

Deila has been forward thinking in terms of his approach to coaching football; self-help psychology gurus have shaped him as a manager and as a man, but there is no amount of positivity that can gloss over just how disjointed and shambolic the last nine months of his tenure at Celtic have been.

He has been badly out of his depth at the Parkhead club.

There is a suggestion that Deila knew before Sunday’s game at Hampden that the gig was up this summer.

If he didn’t know before, he certainly knows now.

The Norwegian had barely time to draw breath following the William Hill semi-final defeat to Rangers, than the inevitable questions came about his future at the club.

Deila quietly and politely rebuffed the queries, but his body language, his mannerisms and his defeated tone suggests he knows well enough that time has run out.

In many ways, he went into that game at Hampden on a hiding to nothing – his fate was sealed before the tie and even a resounding one-sided win would not have enabled his survival, such has been the discord at the club this season.

But with season ticket sales launched this week as Celtic seek to fill seats for the forthcoming campaign and the clamour for Deila’s removal at fever pitch, it is a matter simply whether the Norwegian gets the remaining five league games of this term before the inevitable parting of the ways.

He has continued to speak the same words about relishing the pressure, but his pale, shocked features suggest a different story.

“These times are difficult, but there are difficult times in football,” he said. “I feel drained just now.

"But we will lift it and lift ourselves because we have to.

“You never know what is going to happen in football. I take responsibility for my team and there was lots about the game that was disappointing.

"It was a very disappointed dressing room after the game. The players are hurting. We are hurting as a team and as a club. But we have to go back and get ready to go again.

“You cannot just give up. There are five games now for us and the league has to be the big focus now.

“I am disappointed. I can’t hide that right now but we have another five league games to play. The pressure is always there. I still enjoy it. I need to absorb what has happened and then it is my job to lift the players and lift myself.”

And Deila has appealed for unity as Celtic prepare to close out the campaign.

“We need to all stand together now,” he said. “There is no-one more disappointed, more gutted that I am right now.

"The players are disappointed, we all are. I understand the frustration of the supports and that emotions are high.

“But we have five games to play and we want to win them. It won’t take away the disappointment of the result against Rangers – but we still have to play them and win them. The league was the goal all season and that is what we have to concentrate on.”

Whether he gets either the time he hopes for to cross the line in the race for the title – the club are currently eight points clear at the top of the table – or the solidarity he is looking for remains to be seen.

Deila has been a well-liked manager with an easy-going, warm manner, but patience among the Celtic support has long since reached breaking point.

Kris Commons, despite an indifferent season, was left on the bench for the entirety of Sunday’s game, a decision that irked the majority of Hoops supporters.

But even those who might have defended the decision to go without the playmaker would have struggled to work out why Tom Rogic, Callum McGreogr and Erik Sviatchenko – the three subs who were used – did not start since they gave Celtic greater solidity and balance upon their arrival.

The criticisms that were mounted against Deila’s Celtic on Sunday are the same ones that have been in existence throughout this season./

There seems no Plan B when things are going against Celtic, it takes an age to make a change – Gary Mackay Steven lasted for 70 minutes despite being a little boy lost - and when there is any kind of pressure on this Celtic team, they fold.

The squad itself is bloated with midfielders and yet it was this very area where Celtic were overrun, with Scott Brown, Nir Bitton and Stefan Johansen second to every ball.

Ryan Christie and Scott Allan could have been on the golf course on Sunday, players who have never been given any opportunity to make an impact.

Rangers had nothing to lose on Sunday, while Celtic played like a team terrified to take the test.

The priority now is to get over the line in the league without further drama.

There will be plenty of that this summer.