The combination of a noon kick-off, live television coverage and growing discontent among supporters at recent performances under Deila saw the Scottish champions play in front of just 14,858 fans, one of their lowest home attendances of modern times, as they defeated their Championship opponents 3-0.
But Deila dismissed the relevance of the size of the crowd on an afternoon he believed proved the desire of the Celtic players to secure more success under his management.
“We could have been playing without any people here today,” said Deila. “It was all about playing football and bouncing back from a performance against Dundee on Wednesday we were not happy with.
“The fans who were here were good. They stood behind the team and I’m very happy for that. We have to build up the trust of the fans. It is a win-win situation if we perform. It’s much better to get applause instead of boos, that’s for sure. Hopefully that will continue.
“It’s hard to say how much I needed that victory. You also need to ask how much I needed a semi-final. Of course I want to win the trophy and we now have two more games to hopefully lift it.
“I get asked every week if I feel under more pressure. I didn’t feel that today. I am my biggest critic. I’ve been in this game a long time and when everything is crazy around you, you have to stay calm. I know the players are winners. They hate losing and performing badly. They wanted to show another side of themselves today. I’m proud of the way they did that.”
Celtic wrapped up victory with first-half goals from Leigh Griffiths, Gary Mackay-Steven and Callum McGregor, the latter making his first starting appearance since his arrest and conviction for drink-driving.
“Callum was in very good shape before the incident,” said Deila. “It has taken him time to come back but you always get 100 per cent from him.
“He is a fantastic boy, hard working and good technically. He is especially good in a central position. I’m more happy with him there and it was a very nice goal he scored.”
The only blot on Deila’s afternoon was an ankle injury suffered by Stefan Johansen. The Norwegian midfielder will have the full extent of the damage assessed today. Celtic were unhappy at the challenge from Morton’s Michael Miller, which was not penalised by referee Willie Collum, which forced Johansen to be substituted at half-time.
“It was a hard knock on his ankle,” added Deila. “It’s hard to say how he is. Hopefully it’s not a big injury and he didn’t twist anything. The challenge looked like it was a stretched leg, straight into his ankle. It was not good to watch.”
But Miller, a former Celtic youth player who had been booked just a minute before the incident, insisted the challenge was not malicious. “I didn’t go in to ‘do’ him or anything like that,” said Miller. “I thought I got the ball, the ref did too. It was just an awkward bounce of the ball, just unlucky.”