How long does it take to heal?

How long before the past is buried – not forgotten, because that would be unforgivable and unrealistic – and you wake up feeling like yourself again, or, more accurately, like who you think you are or should be?

Rangers supporters will be wrestling with such feelings in the next few years as they ascend the league ladder. And, on Tuesday night at Parkhead against Juventus, Celtic may get a foretaste of what it will feel like when the Old Firm are finally reunited in the SPL.

A long and painful six years have passed since the summer of the Calciopoli match-fixing scandal, when Juventus were disgraced, gutted, humiliated and banished to Serie B. Since then, they have had more false dawns than anyone cares to remember. This isn't their first appearance in the knockout rounds of the Champions League – they were eliminated by Chelsea in the round of 16 in 2008-09 – but it is the first time that it feels right.

"We gave Chelsea two tough games, but, if we're honest, it wasn't like now," says Gigi Buffon, in his 12th year between the sticks. "Now it's different. Now, we're much more intense."

Being managed by "Mr Intensity" helps. As a player, Antonio Conte was the kind of midfield enforcer who was just as intimidating with his icy gaze as he was with his crunching tackles. That single-minded focus and workrate have been transmitted to the side since he took over last season, leading them to the Serie A title after a triumphant, undefeated season.

But there has been a twist that has cemented him as a legitimate top manager, and not just a sideline chest-beater who gives motivational speeches. Shortly after his appointment, the club signed Andrea Pirlo on a free transfer. AC Milan had deemed him surplus to requirements, and, at first glance, Pirlo did not fit Conte's high-energy 4-2-4 formation.

He didn't have the legs to be one of the two central midfielders and, while his pin-point passing and creativity were appreciated, there were doubts over whether he could still contribute consistently. In addition, Juventus had just signed a top-drawer central midfielder, Arturo Vidal, to go with Claudio Marchisio.

Conte, though, found a way to make it work. He experimented with a three-man midfield, first in a 4-3-3, then in the current 3-5-2. Vidal, Marchisio and Pirlo blended perfectly, showing a natural chemistry. They glide easily around the middle of the park, filling each other's positions when one goes forward. It is no exaggeration to say that Juve's central midfield may well be the best in Europe outside the Camp Nou.

At the back too he has found solutions. His three-man defence is composed of three Italian internationals: Leo Bonucci, Andrea Barzagli and Giorgio Chiellini (who probably won't be fit in time to face Celtic). The Swiss international, Stephan Lichtsteiner, is a reliable option on the right, and, on the other flank, Conte showed pragmatism reinventing Kwadwo Asamoah – normally an elegant midfield playmaker – as an up-and-down wingback.

Conte's other success is a personal one. He has made Juventus more likeable to neutrals, no mean feat given recent history. Not only is the side fun to watch, he has also poked fun at himself, most recently over his hair implants. Conte had the procedure done 12 years ago, much to the hilarity of opponents, who used it as a constant wind-up. But now Conte has mellowed to the point that, last week, he appeared on a satirical TV programme that Photoshopped a cat on to his head.

Juventus' main problem this year, like last season, has been up front. There is an obvious drop off in quality between the defence and midfield on one hand and the attack on the other. Beppe Marotta, Juve's general manager, has talked about the importance of signing a "top player", but for the past 18 months they have failed to do so, despite aggressively pursuing the likes of Sergio Aguero (before his move to Manchester City), Robin van Persie and Luis Suarez. They finally managed to secure a top centre forward – Athletic Bilbao's Fernando Llorente – but he won't be joining until the summer.

In the meantime, they picked up Nicolas Anelka on loan from Shanghai Shenhua to bolster a strikeforce in need of help. None of them are terrible (though some may feel differently about Nicklas Bendtner), but none are consistent game-changers. Mirko Vucinic doesn't score enough, Alessandro Matri is too rough around the edges, Sebastian Giovinco is too small and slow and Fabio Quagliarella too inconsistent. Conte rotates his team in the hope of finding a combination that works: sometimes he gets it right, too often the midfield has to bail out the attack.

Still, despite this, Juventus have been formidable on all fronts. Under Conte, they have lost just five times in 20 months. While they have had a recent wobble domestically – they are still top but went through a spell where they only won one of five in all competitions – Conte insists that's all it was: a wobble.

The club insist it was because they changed their training regimen over the winter break, working harder and longer than usual in an effort to build up stamina so they could peak later in the year – April, to be exact – when it will be crunch time in Serie A and the Champions League.

Of course, if Neil Lennon and his men have their way, they won't get to April in Europe. Having seen how Barcelona fared over two legs against Celtic, Juventus are taking nothing for granted. Privately, however, they note that they are a very different side from Barca.

And they are right. Barcelona's possession and short-passing game played into the hands of Celtic, who found the right tactics to stop them. Juventus, however, are just as comfortable sitting off an opponent and outworking them: they are a far more blue collar side than the Catalans and would see no shame in settling for a draw at Celtic Park if that's what it takes. There is nothing wrong with winning through workrate and intensity, simply wearing down the opposition. That, too, is a legacy of Conte, one left over from his playing days. And he's proud of it.

The long climb back isn't yet complete. But now Juventus can see the clear blue sky above. And they believe they know the path back to the summit.