Speaking today, the Celtic manager said: “As an exercise in testing ourselves and measuring ourselves we did that and the players understand the levels required, and it’s up to me and the collective to chip away at that gap.

“You’ve been exposed to that level so you know the level required. That should be your measurement from now on.

'You’ve got to take that mentality into the domestic competition, and if we do that then you give yourself the chance to be successful.'

“The idea is to take the learnings from the Champions League and put them into the Premiership and cup competitions to try and raise our level of football to be successful domestically and put 12 months of work into trying to be more successful in the Champions League.

“I’ve seen them grow through the games even though the results don’t reflect that. The way they’ve taken on the responsibility and tried to play our football and knowing the way to go to get to that level.

“You’ve seen that domestically because our performances there have been excellent and the goals we’re scoring are showing the lessons learned from the Champions League.”

The manager has been clear in his ambitions to ensure this club and this group never stops and continues to progress in their football which, in turn, aids their goals of lifting more titles and gaining more success in Europe.

To do that, Ange Postecoglou is already targeting players for the upcoming January transfer window and beyond, and says he and the club are ready to be aggressive in the market to ensure they continue on their upward trajectory.

He added: “If you cast back to the winter window last year, we were really aggressive even though we were in a decent position in the league and we did that in the last window as well.

'If we’re going to make those strides (in Europe) I don’t think you can quicken the process but you can accelerate our ability to bridge the gap whether financially or on the field by being really aggressive in the transfer market.'

“That means we have to take opportunities when they come along and maybe pre-empt them to capitalise on things.

“That can be unsettling because it means we have a high turnover of players and not because we want them to leave. If players are happy here and performing then we keep them.

"But it means if players do well and want to move on to pastures new, then we need to be able to ready, able and willing to facilitate that and make sure we replenish that with something that can take us further down the road.

“You have to look a couple of windows ahead every time and project potential outgoings and areas you need improvements in, and my feeling with that is if you can do that before it happens, then you’re in a better place to make better decisions.”

Manager: Squad has already improved from the Champions League