The pressure has been ramped up on 39-year-old Deila, who succeeded Neil Lennon in the summer, following the 1-0 home loss to Premiership leaders Hamilton Accies on Sunday.
The defeat leaves the Scottish champions not only lying sixth in the table, but with only four victories and two defeats from their eight league encounters this season. They have dropped ten points in all.
To place that in context, in romping to the championship last season under Lennon, they shed only 15 points across the entire 38-game campaign, losing only once in the process.
Throw in the fact that Deila’s Celtic were, effectively, twice eliminated at the qualifying stages of the Champions League, and the new man has hardly had his troubles to seek.
Yet Mulgrew, who missed the defeat by Hamilton because of injury, contended yesterday that at close quarters Deila regularly demonstrates why his methods and ethos will ultimately produce the desired results.
“He’s on the training field every day working hard,” said the midfielder. “He’s always trying to make us into a better team. He wants performances as well as results. I see him day in, day out, and everything he does shows he’s definitely the man for the job, plenty of stuff, and we’re all 100 per cent behind him.
“We just need to stop talking about it and do it. There’s been a lot of talking but it’s up to us to get on the pitch and just do it.”
Mulgrew has targeted next Saturday’s trip to Ross County for a return from five weeks out following a knee injury he picked up playing for Scotland away to Germany. And he points to one of his last club outings – a 6-1 drubbing of Dundee United in Glasgow seven weeks ago – as evidence that players’ performances, rather than Deila’s promptings, account for the club’s faltering form.
“That game was one of the couple of times this year when things have clicked into place,” added Mulgrew. “There has been nothing changing between games so when it’s not happened that comes down to us. The manager has some good ideas. Sometimes it’s not always going to come off but it is important that we find a way to win the match. All the time it is about winning. If you can do it in style, fair enough. But we need to start winning.
“Things just don’t fall into place – you need to work at it, especially when a new manager has come in from abroad with different ideas. We’ve got to be ready and take responsibilities as players. A lot of the time the manager takes the flak but we have got to hold our hands up, and step up and be counted. It’s up to us in the end, we are on the pitch and need to do our jobs.”
In the wake of Hamilton’s win on Sunday – their first competitive victory at Parkhead in 76 years – Celtic captain Scott Brown accused some of his team-mates of hiding.
Mulgrew put Brown’s outburst down to the “heat of the moment” and the midfielder’s passion. “Sometimes you get caught cold after a game when you are still disappointed and you say things you don’t mean,” said Mulgrew.
“I haven’t seen his quotes, I don’t know exactly what he said but I know what Scott Brown is like, he is passionate, he wants to win like everybody does.
“Maybe he has said something in the heat of the moment after a game when he is very disappointed. But I am sure Scott Brown wanted to win just like everybody else did so everybody has to stand up and be counted.”
As well as Deila coming in for criticism from increasingly disgruntled supporters, many also remain unconvinced about some of his signings. Aleksandar Tonev, Mubarak Wakaso, Stefan Scepovic and Jo Inge Berget, in particular, have come under scrutiny recently, the latter two not leaving the bench against Hamilton at the weekend.
Mulgrew was asked if the new players were aware of how high expectations were at Parkhead. “If they didn’t before they must [know] now,” continued the 28-year-old.
“There is pressure on us now to start winning games. There is [pressure] every game but especially after a defeat you need to come back out fighting. It wasn’t good enough all round [against Hamilton]. We all know that.
“There has been times this season when it hasn’t been but if we take one or two chances in the first half then it is a different game. We didn’t do that and things changed, they got the goal to make it difficult for us.
“We all have to do better as a group. I don’t think confidence is an issue, I think that is fine. But it is time we picked up results and we need to start doing that in the next match.”
Speaking at his club’s Lennoxtown training complex where he helped publicise the charity donation from club sponsors Magners of £18,300 to Celtic FC Foundation, Mulgrew also expressed surprise that Lennon has yet to land another job.
“I am surprised he’s not had something quicker but I’m sure he’ll get something and do a good job,” he said. “He’s a top, top manager and really has the credentials to be a manager in the Premier League, there is no doubt about it.
“His motivational skills, his tactics and the way he manages players is second to none. He’s definitely the best man-manager I have played under, so far. He’s a great man manager and I just hope he gets something.”