Scott Brown's absence as he prepares to go under the knife to remedy an adductor problem which has sidelined him since the first leg of Celtic's Champions League last-16 tie with Juventus has emphasised just how important he is to Neil Lennon's side.
That was never more starkly brought into focus than at Dingwall on Saturday when the league leaders allowed a quickfire 2-0 lead over Ross County to first be clawed back, then overtaken.
Among Lennon's post-match accusations aimed at the stars who had so badly let him and the club's supporters down was the claim they lacked players in certain positions.
Most of all, they lacked a leader of men, Brown's most important quality, and the one which first earned him the armband – to the surprise of many – when Tony Mowbray was manager three years ago.
Since then, Lennon – himself a former Hoops skipper – has seen no reason to replace Brown with anyone else at the front of the line when the team runs out.
The man who first brought Brown to Parkhead, Gordon Strachan, also saw fit to make the 27-year-old the captain of Scotland when he selected his first team for the friendly against Estonia last month.
Now, while Brown awaits a date to undergo the surgery which Lennon and Strachan hope will allow him to return to full mobility and effectiveness, his enforced absence for club and country is being sorely felt.
The belief is that, such is his pride, determination and motivation, he not only produces a performance of 100% commitment whenever he plays, but, more importantly, he demands those around him follow his lead.
Even if half of the team selected to face Ross County at the weekend, or Motherwell in the previous SPL outing, had done this, Celtic would have been much closer to crossing the finishing line in the SPL title race.
Lennon had nine players out of action at the weekend, but he makes no attempt to underplay the significance of being without one in particular, his captain.
The manager said: "Scott is influential, and we have certainly missed him in the last couple of games.
"But I think he will need surgery and he will be out for a while."
So, the baton of responsibility will have to be carried by those who remain fit enough to play as this exhausting roller-coaster of a season enters the final few loops.
It should be a chance for some fringe players to step forward and show what they can do.
However, a few were afforded that privilege at Dingwall, and failed to grasp the opportunity.
Asked if some players on the periphery might now get a run, Lennon answered: "It's up to them. But I didn't see much evidence on Saturday that they are going to make a huge difference to us.
"I was disappointed in some of the players we brought in as well. It's difficult coming in for one game in five, and it was a difficult game on Saturday with the conditions.
"But we need to get better and we need to do better. I need some character, and we are lacking in it."
The fact the constant run of midweek games – something Lennon accepts is part and parcel of trying to be successful – has finally come to an end is welcomed.
It will allow the manager and his coaches time to work with the players to eradicate the shortcomings which have crept into their game.
But if anyone thinks it will be the signal for a few days extra rest, the late winner by Ross County has put paid to that.
Lennon has other plans for them this week, and said: "They are going to need the break from games this week because they are going to get worked quite hard, some of them.
"Others, we will give them the chance to recover and come again."
The manager's anger was evident for all to see at Dingwall. And, while he may have calmed down by the time he got back to Lennoxtown, it will take more than a few days' hard graft and a return to form against Aberdeen on Saturday to get all of his players back into his good books.
His main grouse is that standards have been set, and he refuses to allow anyone to drop below them as a result of not having their mind on the job.
"I was pleased with them last weekend against St Mirren in the cup tie," said Lennon. "I was pleased with them on Wednesday in Turin.
"But, at Motherwell, then again on Saturday, I was really disappointed."
Disappointment which brought harsh words to his lips post-match.
His barbed comments about some players looking like they would rather be earning their cash elsewhere was designed to raise eyebrows, and alert those not privy to dressing-room chats that questions about motives are being asked.
It might have been natural to consider Gary Hooper – still refusing to sign a new contract and widely tipped to be on his way in the summer – to be one of the men in Lennon's firing line.
But he exonerated the striker from his criticism as he was one of the few who did show total commitment against Ross County.
And, when asked if it was other players he thought might be looking to move on, Lennon said: "Just looking at the way they are playing at the minute, or their body language, it looks like it to me.
"I thought we were sloppy, particularly at the back. It was difficult on their pitch, but that's no excuse."
Just as no excuse will be accepted if his side – even without the influential presence of Brown – do not lift themselves back into the groove which pre-empted this current malaise when they face Aberdeen on their return to Parkhead this weekend.