C eltic are overjoyed that they can no longer catch opponents by surprise.

Neil Lennon was piqued when he recalled that his side were thought to have "novelty value" when the draw was made for the Champions League group stages, but that attitude was obliterated when Barcelona were overcome at Celtic Park in November. The tendency is to hold tightly on to the memories of that evening, as though every moment of the encounter must still be treasured, but its true worth was in forcing people to reassess Celtic.

No side that defeats Barcelona can regain an element of stealth. Juventus, for instance, will be acutely aware of the way that the influence of the crowd and the occasion on a European night in the east end of Glasgow can galvanise the home side. It is common to overstate the importance of the atmosphere, especially when elite footballers regularly perform in intense situations, but there is an emotional charge to the stadium when the circumstances are right. It would be foolish to rely on that quality, nonetheless, since Juventus were psychologically strong enough to remain unbeaten in Serie A throughout last season.

There is a hierarchy in every tournament, and the likelihood is that Celtic will more readily adapt their tactics to the situation than Juventus. The Italians will consider their customary approach to be robust enough to survive an away trip to Glasgow in the last 16 of the Champions League. It was Lennon, for instance, who spoke yesterday of "maybe thinking about doing something different. But we might not". He was enjoying being coy, although he did talk last weekend of liking the way his side played against Udinese in the Europa League last season, when he matched the Italian side's 3-5-2 shape. Juventus also use that formation.

The machinations are the product of a heightened state of awareness. The competitor in Lennon relishes the tactical strategising, and the sense of empowerment that comes from making such stark progress. Little escapes his attention, including the value of speaking his mind, as Murdo MacLeod, the newspaper columnist and former Celtic player, discovered recently when he was the subject of the manager's ire for critical comments. Lennon revels in undermining slights against his club.

"We've caught a lot of people's attention and we have been underestimated as this physical, up-and-at-'em-type of British team, which is exactly what we're not," he said. "It's just a cheap shot, born out of ignorance that we've had to put up with for a long time. I don't need to use it to motivate the players, they know what's at stake and how much they've put in to get here. We've got plenty of skilful, technical players who, on a big pitch against quality opposition, will perform. Mainstream, down south, they've been very encouraging towards us, in terms of respect, coverage. Now people see us a serious club."

There is no doubting Celtic's sense of self-assurance. Lennon described the victory over Barcelona as "iconic", and there is a bullishness about the team now. Details are still to be finalised – Georgios Samaras's fitness will be assessed at lunchtime today, while Efe Ambrose will be in the squad if his conditioning will allow following the flight back to Glasgow after Nigeria's Africa Cup of Nations triumph on Sunday night in Johannesburg – but the players are being encouraged to believe that progress to the next round is possible.

A form of motivation is present when a manager discusses his team in public. The draw for the knockout stages was made so long ago that trepidation may have settled in the players' minds. Even so, the challenges posed by this Juventus side will seem mundane compared to the prospect Celtic previously faced of trying to cope with the brilliance of Lionel Messi. The Italian side's shape means that the wing-backs need to be countered effectively, so Celtic will have to be dynamic and disciplined on their wings, while a midfield trio will need to cope with the core of the Juventus side. It might not be enough to seek to restrict the visitors, though, when the second leg in Turin is still to come.

"Conceding an away goal can be damaging," Lennon said. "I would like to take a lead to Turin, but they're very hard to break down, they're very strong defensively. It might be a night of patience. We might only get one or two chances. It will be different from Barcelona – we'll have more of the ball and it will be more a case of us trying to break them down rather than the other way around. It could be a war of attrition in midfield. And it might be they'll try to counterattack and suck the life out of the game when they can, so we have to show no signs of frustration. But we have a fantastic team collective and some individual players who can turn a game very quickly."

Returning Celtic to a place among the leading sides in Europe is a source of professional satisfaction for Lennon, but also a personal cause. He understands intimately the resurgence of pride among the Celtic supporters, since there is a precious quality to be found among the euphoria. "We have given the fans something to believe again, something to dream about," the manager added. "That's been missing for a long time."