JOHN HARTSON is the first to hold his hand up and admit he got it wrong. The former Celtic striker was among the dissenting voices that questioned the appointment of Ange Postecoglou when the Greek-Australian was unveiled as Neil Lennon’s permanent successor last summer. He readily admits to feeling underwhelmed when he first heard the news as he knew very little about the coach.

The former Wales internationalist reckoned his old team’s chances of winning the league this term were at absolute zero as the campaign kicked off but with Celtic three points clear at the table’s summit as we head into the final eight games of the season, Hartson is more than happy to eat his words.

Between the changes in the playing squad, upheaval in the boardroom and a fanbase that had fallen out of love with the team, Postecoglou did not have his troubles to seek when he took the job. But Hartson thinks he has met all those challenges head on as he considered the progress made at Parkhead.

“At the start of the season, Celtic couldn’t win the league: impossible,” Hartson explained. “It was a mess that Ange took over.

“At the time, I said it was a transitional period. Look at it: they lost their centre-forward, their best player. They lost their best centre-half. They lost their captain. They didn’t have a manager. The chief executive left. And the team were just: what do we do now?

“Brought in Ange Postecoglou. Nobody has ever heard of him. No disrespect, but people were asking ‘who is this guy?’ Even me. I said I thought they should be going for somebody with more of a name.

“It was total ignorance from myself, but I wasn’t the only one. There were plenty of us that were ignorant, even the Press. Who is this guy? What’s he done? Where’s he been? But he’s come in and he’s just done unbelievably [well].

“The players that he has recruited, the style of football. He has united the full stadium from being very toxic for periods last season. The way that they play, the Celtic way, front foot, aggressive, go forward, score goals. To think that they’re the position they are in, and they can possibly win the league, is just remarkable.”

Hartson puts much of this turnaround down to Postecoglou’s work in the transfer market. The likes of Jota, Kyogo Furuhashi and Liel Abada were identified, brought in and have formed a fluid attack relatively quicky, while others have had stalling careers kick-started by the new manager.

Hartson recalled: “He didn’t have a player. A couple of weeks ago, Celtic had two players on the pitch - I think it was [Greg] Taylor and [Callum] McGregor - who weren’t his signings.

“Think of the impact his signings have made. They bring a young lad over from Benfica on loan. What a player. Look at Abada. What about his numbers? Incredible. Fourteen goals he has got from right wing.

“Look at Kyogo and the other Japanese international, Reo Hatate. And then the likes of [Joe] Hart. They wrote Hart off before he had even made a save.

“[Anthony] Ralston has been excellent. [Carl] Starfelt has come in for a bit of criticism. I still think there are frailties defensively at times, but the way they play – expansive, aggressive, outscore the position, front foot, high intensity, what he demands from players every single game. And those demands won’t stop.”

Finishing the campaign with a league winners’ medal draped around his neck would cap a remarkable first season in Scotland for Postecoglou but Hartson thinks even if the Greek-Australian pips Rangers to the title this term, he still has a bit of work to do before he can be considered alongside the club’s managerial greats.

“You look at Gordon Strachan – he entered the latter stages of the Champions League, he got out of the group twice,” Hartson reasoned. “Martin O’Neill got to a UEFA Cup final, the best achievement since Jock Stein, and won the Treble.

“Ange has united everyone, united the crowd and brought everyone together. He has given everyone a belief, that’s what he’s done and the team are playing very well.

“I think he will recognise that he has to win trophies and he has already won the first trophy this season, let’s not forget that. The guy won a trophy after being at the club for six months. That takes the pressure off because I don’t think he sees it like that.

“I think he is very humble, I think he has got so much desire and wants to win. He wants to improve players, which he has done, and I think he will appreciate if he leaves Celtic down the line with league titles and four or five cups, he will be considered as with all the other greats.

“You look at Lenny – he did very well. Gordon Strachan won three titles in a row. Martin had the UEFA Cup final. So he will know the great managers that were here before him.

“He knows the history, he gets the club, he comes from humble surroundings and he speaks exceptionally well. He doesn’t slam his players. Once or twice this season he has questioned a performance but in general he is always very positive and I think that rubs off on his teams.”

John Hartson was promoting exclusively live Premier Sports coverage of Dundee v Rangers this Sunday from 3.30pm and Dundee United v Celtic this Monday from 7.15pm. Premier Sports is available on Sky, Virgin TV and the Premier Player from £12.99 per month, and on Amazon Prime as an add-on subscription.