“KEEP the pressure on. The more we're a team that they don't want to play against, the more effective we'll be.”

It must be exhausting to play against Celtic right now.

You spend the majority of the match chasing these blurs of green and white about the pitch, every step wearing you down as it’s one more second wasted without getting a kick of the ball. And when you do get it… good luck trying to keep it. They appear like a swarm of green and white bumblebees; buzzing, badgering and bothering until you inevitably can’t bat them away or outrun them any longer and it’s back to square one again. Pass, pass, pass. Chase, chase, chase.

But nobody should be surprised. Ange Postecoglou told us all this was going to happen.

Two-and-a-half months ago the 55-year-old became Celtic manager. At the end of his first week, the Greek-Australian allowed the club to mic him up for a training session.

It was less than a week out from the team’s first pre-season friendly against Sheffield Wednesday. The new boss was still getting to know his players and they him.

The resultant three-minute clip went viral among the Celtic fanbase for the glimpse it gave them into Postecoglou’s way of thinking.

After greeting each player by name as they arrived on the training pitch, there was no mistaking what the order of the day was: helping them learn what is expected during a match.

READ MORE: Ruthless Celtic making tangible progress under Ange Postecoglou as another opponent is laid flat on the canvas - Tony Haggerty

"Ball speed's very important for us - ball speed's number one,” Postecoglou directed, even in an abridged version of the session it’s clear there's no half-measures with him.

“Even when we're keeping possession I don't want the ball to move slowly. What does that mean? When we pass it, pass it with purpose.

"We need movement so the next pass is always available and not too many touches on the ball. One or two touches, we move it. We move together as a team.

"Once we get to the front third we've got to be super-sharp and super-efficient. It goes wide, early cross, attack the box, score our goals."

That’s more or less exactly what Celtic have set about doing since then. Although, of course, it didn’t click straight away. In fact, the opposite was true in the early weeks as Postecoglou’s tenure started with no wins in his first three competitive matches.

There was seemingly a lack of urgency in terms of the club’s recruitment policy, as well as injuries and suspensions to deal with, as a 6-2 home humbling to West Ham in a friendly was sandwiched in between Champions League qualifying elimination over two legs to FC Midtjylland.

That Hearts then put the frighteners on even further by beating the Hoops 2-1 at Tynecastle on the league’s opening night just served to throw up some intriguing, if misguided, questions about whether Postecoglou might be prudent to adopt a more pragmatic style until he had the players required to fully commit to his own system.

That was never going to happen. Postecoglou’s belief in his own style of play is total – a cursory read-through of anyone who has ever worked with him tells you that – but what may have been in doubt was how quickly it would take root with the players.

A common theme when it comes to people from Postecoglou’s past is that of time. “It takes time”, “He will get it right if he’s given time”, “Patience is key while his style takes hold” and various other ways of saying the same thing. The problem is you don’t really get a whole lot of time at Celtic, it’s part of being in charge of such a successful club.

That said, the fans were generally understanding that those early weeks had much to do with lack of direction at board level and not the new manager himself.

But while on the outside questions were already being asked, on the inside Postecoglou was busy continuing to instil his philosophy in the players. Just like at that mic'd up training session.

"Read the timing of the pass. Look at your movement, you're always involved. Always involved,” he told the players that day. "If the ball's on the far side, you're not standing there thinking 'I'm not involved'. If the ball comes across you're seeing the next pass and going. Always (be) ready to go at the right time.

"If our movement's good, our passing's good. The ball doesn't stop. That's going to be super-important and remember your reaction if the move's dead.

READ MORE: Ange Postecoglou on Celtic developing a more ruthless streak, qualifying for the Europa League and transfer deals

"If we lose the ball, I fucking want us to win it back. Keep the pressure on. The more we're a team that they don't want to play against, the more effective we'll be. They'll know they can't get a rest against us.

"Just get it into your heads: we never stop. We never stop. We'll stop at half-time and we'll stop at the end of the game when we celebrate. But during the game, we don't stop.

"If the opposition wants to stop that's good for us, we'll fucking take advantage of it.”

Since the Hearts result Celtic haven’t stopped. It’s as if a switch has been flicked.

Six wins, 24 goals, 138 shots, an average of 65.75 per cent possession and 624.5 passes per game. Then there’s the pressing, the movement, the intensity, the flicks and the tricks; it’s everything Postecoglou hinted at in his mic’d up training session so far.

But there was, naturally, no switch. This recent upturn in fortunes and performance has come as a result of the work being done behind the scenes by the players and staff. They are putting in the effort and seeing the rewards, as are the fans.

It’s what the statisticians would call a small sample size but, still, how quickly the players have grasped what is required and expected of them under Postecoglou is exhilarating. And the impact of tactical identity in football cannot be underestimated; just look at Italy’s Euro 2020 triumph.

There are harder tasks to come – Thursday’s second leg against AZ Alkmaar and Sunday’s derby at Ibrox are the two most immediate examples – but the signs so far are overwhelmingly positive.

Celtic have an identity again: they don't stop. It must be exhausting trying to make them.