HARRY KEWELL thought he was intense on the training ground - that was until he joined Celtic and watched Ange Postecoglou running drills.

The Celtic first-team coach agreed to become a part of the Celtic backroom team under Postecoglou last season and has been left hugely impressed by the talent on the pitch and in the coaching ranks.

Kewell - an Australia footballing icon himself - even goes so far as to consider management "master" Postecoglou as the greatest coach from Down Under.

A huge factor in Kewell's judgement is having seen Postecoglou up close and the sheer intensity in training every day.

Speaking to The Sydney Morning Herald, Kewell said: “When people talk about he plays a beautiful way ... I mean, you should see the training sessions.

“These boys are put through it. He demands, every single day: ‘Get that ball, move that ball’.

"Intense? Wow. I feel like I’m intense. He just takes it to another level, but in a good way. I get to see it every day.

"I usually don’t get taken aback by certain movements in certain plays. But when I see certain things, I go, ‘Decent, they’re decent.’

“The one thing he does paint is the clearest pictures. You would have to be silly not to understand it, because he picks out everything and he will show you, and then you can’t argue with it, because it’s there: it’s in black and white, plus it’s in colour, plus it’s on video, plus it’s on the pitch.

"It is as clear as day when it comes to the messages. And I think that’s why the players love it.”

Celtic head into the Champions League group stages this season after winning the Scottish Premiership title last season.

And Kewell insists Postecoglou will stick to his philosophy on the European stage as he hailed the new-look Celtic identity under the manager.

“It’s pretty good to sit back and watch and learn, from I have to say, a master," said Kewell.

“He’s probably Australia’s greatest coach. And now, he’s starting to push up to be one of the greats of the European game.

“What the manager came into last year, and what he’s created ... I mean, you just walk around town and people love him. They love his aura, they love the way he’s a straight talker – he commands the room when he walks in there.

"But the important thing is he’s winning football matches, and [doing it] his way. That’s what’s Celtic have missed just recently is their identity.

"And now I think you can clearly say they’ve got an identity, and now they’re working on that identity to become even better.”

Kewell added: “You only live once, right? So, why not just play the way that you’re comfortable with, and go out there and see it?"