It was the news Derek McInnes suspected but never wanted to hear; his captain, Ryan Jack’s knee injury is worse than at first feared and the midfielder will need a cartilage operation.

That Jack’s presence would have been welcomed as Aberdeen challenge Celtic at Parkhead today is not in dispute.

What the Dons manager will find out, however, is just how effective his side can be without him and, indeed, without other injured players, Jonny Hayes and Peter Pawlett.

Jack was certainly missed in the 2-1 home win against Partick Thistle a week ago as McInnes waits and wonders how long his services will be unavailable.

Still, he was upbeat last night as he looked ahead to going head to head with Brendan Rodgers in what could be a tactical battle in Aberdeen’s efforts to take their first league points at Celtic Park since McInnes assumed control three years ago.

Having a strong defence, he asserted, was not the most important issue when taking on the champions on their own turf.

“There are lots of facets needed to win the game,” he insisted.

“You've got to be good in possession, you've got to be organised, not get too stretched. We need to not allow their players to enjoy the game, but defending properly is a big part of it.”

McInnes pointed to a certain slackness in the Hoops’ back four this season, notably against Hapoel Beer-Sheva in their Champions League qualifying tie, a flaw that offers him hope.

"There have been moments of sloppiness,” he said, “and goals you would not expect them to lose. But sometimes the best form of defence is attack. And when Celtic are potent and free-flowing, and playing off their shape, they ask questions of the opposition.

“That, though, can leave them a bit stretched at times.

"But we've still got to carry a threat to them and pace will be important. That's why Peter and Jonny will be a big miss but we will have to find a way.”

If the Pittodrie party line since McInnes’s arrival has been one of low level hubris, it appears to have been lifted.

Mark Reynolds, enjoying a renaissance this season following a long spell of injury last term, epitomised a slightly bolder approach from the Dons dressing room by openly admitting that he and his team-mates were genuine challengers for the Ladbrokes Premiership title.

“Are we more comfortable being regarded as title challengers now?” he said. “Yes, probably.

“We have never really bothered about whether people consider us to be challengers or not.

“Since the manager came in we’ve kept everything in house, all our beliefs and our aims.

“We always talked about it, just not to the media!

“The manager didn’t put down a party whip saying not to do it, it was just what happened.

“It was always jumped upon when we spoke about it before. The headlines were always ‘Aberdeen think they can win the title’.

“So we were private about it and the mindset has always been to take it one game as a time.

“I think now, though, it’s not such a big deal and it’s just in with the rest of the text.

“The way it has been viewed has changed; it was almost as if it was a case of ‘who do they think they are?’

“But now it’s less sensational because we’ve been there and challenged.”

There are those in Glasgow’s East End who will underline the statistic that Reynolds and Co finished 15 points behind Celtic as last season drew to a close, but with new recruits having arrived at Pittodrie, there is a feeling among the Reds that improvement will be shown this time round.

“Celtic will have weeks where they don’t play well,” he added, “but they’ll manage to win – and that’s what it’s all about.

“If we win, it’s a marker, if we lose it’s early doors.”