ONE of the sticks used to beat Celtic manager Ange Postecoglou in the early part of his reign was that while his attacking style may have been thrilling, his refusal to buckle to pragmatism left his defence vulnerable, and ultimately porous.

It may be surprising to learn then that Joe Hart and the defenders in front of him have racked up the most clean sheets in the Scottish Premiership this season with nine to their name, recording five of those shut-outs in their last six games.

Goalkeeper Hart may be forgiven for taking at least a portion of his satisfaction at such statistics from proving Celtic’s critics wrong, but he is instead delighted to be proving manager Postecoglou right for placing his faith in the likes of himself, Carl Starfelt and Cameron Carter-Vickers in the summer.

“People are all wired up differently, but I don’t really go out to prove people wrong,” Hart said. “My nature is more to try and prove people right.

“All of us - myself, Jura (Josip Juranovic) when he’s played, Carl, Cam – we’ve all been brought to the club because they’ve believed in us.

“Obviously Anthony (Ralston) has been here, Greg (Taylor) too and the other guys who were here before they’ve believed in them too, but we’ve been brought here because they believe we can do a job.

“I’d like to think we’re doing a good job proving those people right at the moment.”

What has been the key behind those improved defensive performances though?

“It’s defending as an XI and attacking as an XI,” he said. “The manager has made that very clear from the moment he came in.

“Everyone is connected, right the way up to the matchday squad of 18 or however many it is for a cup game.

“We’re all connected, we’re all involved, and we’re all responsible.

“I think doing it as a collective is really helping.”

Hart has played under some of the best coaches the world of football has to offer, but few have demanded as much of him as Postecoglou, particularly in regards to using his feet rather than his hands.

But even at this advanced stage of his football career, Hart is happy to put himself through the necessary hours on the training field, and take the lessons on board that his manager imparts upon him, for one very simple reason; he trusts the process.

Hart is at the stage of his career where he questions the purpose of everything he does in his preparation, but it is crystal clear to the former England number one just why Postecoglou is demanding the things he does from him and his teammates.

It is that clarity of message and purpose that has Hart and the rest of the Celtic squad running through brick walls for their manager, and why Postecoglou rates as one of the best managers the 34-year-old has worked with.

“In terms of the style of play, I’ve been very impressed by the manager and the way he puts things across,” he said.

“You can be very blasé and just tell people that you want to play out from the back, but there’s a process to it.

“What I love is that there’s reasons behind what I do. For me personally with the point I’m at in my career, and with my understanding of football, I like to ask why we are doing something. And I don’t find myself asking why much with this style.

“It makes a lot of sense and it is perfectly explained. I’m really enjoying it, I’m really loving working under him.

“It’s testing, but in a good way. There’s an awful lot of information, but the reasons why we do things are very clear, and that’s the way I like to work.

“That’s what I’m really enjoying.”

On a personal level, Hart’s influence has been credited by his teammates as a huge factor in their recent fine form, but his performances on the pitch haven’t been bad either.

Yes, he can still send the hearts of Celtic fans aflutter on occasion as he gets to grip with his dribbling and passing, but it is in his old-fashioned shot-stopping that he has been impressing of late.

A quiet afternoon against Motherwell on Sunday was punctuated by a world-class stop from a deflected Sean Goss effort, before he got up to spread himself to also deny Tony Watt.

“I feel good, I’m loving being a part of the style of play we’re involved in,” he said.

“Probably to the guys who look at stats in terms of shots faced, you could say I’m not facing many, but I feel very involved and very attached to the game, however that may be.

“Every now and again I have to make a save, the guys don’t ask me to step up and do that very often, so I’m just trying to do my best when that comes along.”

The next stop for Celtic during this hectic festive fixture schedule is the Highlands tonight, as they travel to Dingwall to face Ross County.

It is hardly the ideal preparation for Sunday’s League Cup Final against Hibernian, but Hart knows that this match has just as much value in the context of Celtic’s ambitions for the season as a showpiece occasion at Hampden.

“Sunday doesn’t even come into it,” he said.

“We go to Ross County with all our focus, all our energy, and all our squad ready to do a job on the night.

“It’s going to be a tough game. We want to put ourselves in the best position to do well and hopefully pick up maximum points. We are fully aware of the threats they pose.

“There’s no getting away from what we’re trying to do here. We focus on it full-time, we put games to bed quickly, and we focus on the next one.

“Ross County are going to get our full focus. The game on Sunday is put to bed, everyone’s thoughts and focus is on Ross County now, and after that we’ll look to the cup final.

“That’s how it is.”