Although the Italian considered Barcelona's weekend defeat to Malaga to be an anomaly, he has plans to punish the visitors if they are lax at the back on Tuesday night.
"The way they play, they can concede spaces in behind and we must know how to take advantage of them," Allegri told the assembled press.
"Whether they start with three or four center-backs matters little, we will have to do very well to get the better of Barcelona, but we know their characteristics.
"My team has to be aware of the means to this end, the steps we must take are technical and psychological.
"You can win or lose these games, but you have to play them thinking that you can win. If we don't think that we can overcome Barcelona, we will be beaten from the start."
Facing the Azulgrana less than two years after his Old Lady outfit lost 3-1 in the 2014/15 final, the coach is confident that things have changed for the better at Juventus Stadium since then.
"Barcelona are the strongest team, but we have grown in confidence and self-esteem," Allegri said.
"It's a different match this time around. It's not a simple game and you have to keep your options open.
"Of that final, only two of our players remain, [Gianluigi] Buffon and [Leonardo] Bonucci."
Much like Paris Saint-Germain, the Serie A leaders face the second leg back at the Camp Nou, creating a tricky scenario for Allegri's men.
"When you play at home first, you try not to concede," he added. "But tomorrow will be difficult, as we have to score.
"Their comeback against PSG has taught us that nothing can be taken for granted, especially at this level."
Luis Enrique: Andre Gomes? It's pathetic to blame one player for a defeat
Plenty of criticism has been directed at Andre Gomes after Barcelona fell to a 2-0 defeat against Malaga last weekend, but Luis Enrique gathered his player and hit out at those who have made the Portuguese midfielder a scapegoat.
Stressing that football is played by 11 players and not just one, he considered it harsh that so much blame has been attributed to the 23-year-old.
"In my view it is pathetic and sad to blame one or two individual players for a defeat," he said during his pre-match press conference for Tuesday's clash with Juventus.
"This is a team sport and that seems unfair to me.
"Andre Gomes could be a replacement for [Sergio] Busquets."
Reflecting on the Malaga loss further, the coach was adamant that the Blaugrana deserved something from the game and was concerned only by the result, not by the performance.
"The Sevilla and Malaga games were both good, but the [Malaga] result was a disaster and unfair," he told those in attendance.
"We were better than Malaga, but they condemned us for the only mistake we had.
"We shouldn't go crazy when a defeat comes along, while we also shouldn't go crazy when we defeat Sevilla comfortably."
After dismissing questions about Neymar potentially missing the Clasico through suspension, Luis Enrique looked ahead to the match at Juventus Stadium and admitted that the opposition is a force to be reckoned with, but that Barcelona expects to play well.
"Our objective is the same as always, which is to play a great game no matter who the opponent is or what stadium we're playing in," the Asturian said.
"Yet defeating a team this strong will always be difficult.
"It is a similar Juventus team [to the 2015 Champions League final], but with some players having left and some new ones having signed.
"I don't know if the team of two years ago is better or if the current team is."
One final topic of discussion was the suspension of Sergio Busquets and how the Catalan side would look to piece without their starting defensive midfielder, but Luis Enrique isn't overly worried.
"He is a vital player, both because of his level of talent and his importance in the unit, but we are more than capable of coping with his absence," he said.
"It's normal for some players to miss matches at some point during a long tournament.
"This cannot be an excuse."
Lewandowski misses training again as Neuer returns
A shoulder injury sustained against Borussia Dortmund has kept Bayern Munich forward Robert Lewandowski out of training for two consecutive days, leading to concerns over his fitness.
The German champions host Real Madrid in the Champions League quarter-final stage on Wednesday night but Lewandowski's participation in that game is now doubtful.
Coach Carlo Ancelotti is still unsure if he will be able to call upon the Poland international and is waiting on tenterhooks for any news about the forward's recovery.
There was positive news for the Italian though in terms of Manuel Neuer's fitness, with the goalkeeper having returned, as expected, to training on Monday.
As such, Bayern's custodian will definitely feature against Los Blancos.
Higuain: I cried when I left Real Madrid
As he prepares to help current employers Juventus prepare for their Champions League showdown with Barcelona, Gonzalo Higuain has revealed how difficult it was for him to say goodbye to Real Madrid.
The Argentina international starred for Los Blancos from 2007 to 2013, scoring 121 goals in all matches.
He departed for Naples in 2013 and spent three extremely successful seasons at the Stadio San Paolo before joining Juventus in a highly controversial transfer last summer, and he has reflected on the moves to both clubs.
"Football has made me cry with both joy and sadness," the 29-year-old said in an interview with El Mundo.
"When I had to leave the [Estadio Santiago] Bernabeu, of course I cried.
"It was the same when I left Napoli. I always held a great affection for the places I've played and when I had to leave both clubs it was a very sad time."
Although he insisted that his Real history doesn't have him any more fired up to face Barcelona in Europe, he is nonetheless excited for the occasion and confident the Italian champions can progress.
"Everybody knows how much I love Madrid but now I'm playing for Juventus," he continued.
"It will be a special game because we can eliminate a big rival and that would give us a lot of confidence for what is ahead.
"For many years, Barcelona have been at the very top of the elite but we are well prepared to face them.
"We trust in ourselves and are satisfied we can advance because we are ready to fight until death in both games."
Buffon: Any team with Suarez, Messi, and Neymar has a devastating attack
Ever the candidate to be in the line of fire, Juventus goalkeeper Gianluigi Buffon is well aware of what he's up against when Barcelona come to town on Tuesday night.
Luis Suarez, Neymar, and Lionel Messi are due to align in front of him for the Champions League quarter-finals first leg, although the Italian knows that the latter is yet to hit the back of his net.
"Obviously a team that plays Suarez, Messi and Neymar has a devastating attack," he told reporters. "All three are altruistic, have a great attitude, play with a lot of joy, and have earned a huge amount of respect.
"I have never conceded a goal to Messi, I've faced him a few times but always with a great defense."
Comparing the current teams to the ones that destroyed the 2014/15 final, the veteran is confident that Juve have improved since that 3-1 loss in Berlin.
"Barcelona have changed very little, our more," Buffon continued. "We will find out if the gap has been closed.
"My memories from the final make me cautiously optimistic for the present day, as we have grown. On paper they are stronger, but we have gained two years of experience in Europe since then.
"I will think twice as they are the most difficult team to beat, and sometimes it can happen that your opponents are better than you. Then you have to shake hands and congratulate them.
"Their comeback against Paris Saint-Germain was a great lesson from a sporting and social point of view. With that, they taught us that anything is possible."
Incredibly complimentary about Barcelona in his pre-game media briefing, Buffon then pointed to Gonzalo Higuain and Paulo Dybala as key Bianconeri players who can lead Juve to the last-four.
"We are probably playing the strong team we could face and it will be nice to measure ourselves against them," added the shot-stopper.
"With players like Dybala and Higuain, if they are at 100 percent, that gives us confidence."
Dybala: I don't want to be Messi, I don't want to be Dybala
At just 23, and in a Juventus dressing room with players such as Gianluigi Buffon and Gonzalo Higuain, Paulo Dybala feels loved and important but, ahead of the Champions League clash with Barcelona, wants the comparisons with countryman Lionel Messi to stop.
The Bianconeri will look to the youngster for much of their attacking thrust and, if the game goes as he would like, he'll finally be able to step out of La Pulga's shadow.
As we approach the tie with Barcelona, how are you?
"Happy. After the injury and losing out on games with the national team, I had a good performance on Saturday. I played for 90 minutes which gave me confidence and put me in good shape for the Barcelona game. I think the match comes at the right time because we're playing better than them. "
You look optimistic.
"We are in our best moment of the season. That's what I see after eliminating Napoli in the Coppa Italia and having won against Chievo and Sampdoria in Serie A. Games like Barcelona are motivational for us."
Juventus did their homework, unlike Barcelona who lost at Malaga and made winning LaLiga more complicated as a result.
"You have to make changes when you play in the league and then the Champions League straight after. Barcelona will absolutely want to recover from the defeat [against Malaga], but we're a very strong team at home."
In spite of that, isn't it a little scary to pit yourself against a team that came back from 4-0 down?
"We shouldn't be afraid of anything. Respect, yes, but not fear. This is the best time to face Barcelona. They came back against Paris Saint-Germain, but PSG didn't play that match as they should. The 6 -1 serves as a lesson to everyone, and I say it before playing the first leg against them. "
It will be the first time you face Leo Messi.
"I respect and admire him a lot, but I play for Juve and Leo for Barcelona. I will do my best to win."
Is there one of your biggest reference points in the game?
"I watch Barcelona because I have always liked their style of play, and now with Leo even more. He has won many Champions Leagues and I have none. I want this to be my first one."
It's not difficult to find parallels between you and Messi. Same position, you both came to Europe very young ... does it bother you that in Argentina you are considered his successor?
"People have to know that I am not Messi. I am Dybala and I want to only be Dybala, although I understand that there are comparisons. There's only one Messi, as there was only one Maradona. You can't replace players like them and it's a huge burden that people have expectations about me. I will try to give maximum effort in every game - including those that Leo can't play for the national team. "
Can you imagine playing at the Camp Nou as a venue one day?
"[Pause and sigh] Three years ago, in Palermo, I didn't think I would go to Juve. Therefore, I enjoy the day-to-day and I don't think beyond that. I am happy here, where everyone everyone loves me very much. "
Your face lights up when you talk about Barcelona.
"It's because we Argentines feel very identified with Messi. He's an idol, I've always said that and, well, in the club there are other great players, such as Neymar."
What virtues and what defects does this Barcelona have?
"The best players are their forwards. No need to talk about them. The worst thing is that they are a team that suffers when they don't have the ball. We have to try to take it away and prevent them from playing their natural game. . "
"He's the one that makes the team tick, but Barcelona have many other options. The coach will find the best solution. Even the goalkeeper, with the quality he has, could play there!"
I was just going to ask about Marc-Andre ter Stegen ...
"He has a great calmness on the ball and can play with both feet. That's all training because a Barcelona goalkeeper has to be prepared for that; look at Victor Valdes for example. For us, Buffon is a colossus in his position. What Gigi has done hasn't been achieved by anyone. "
Your team has a lot of experienced players in it. What has Dani Alves said to you about Barcelona?
"I have a good friendship with him, we always talk a lot. I ask him things about Barcelona because he obviously knows them very well and I always try to listen to him, lean on him. He has a great right foot and plays in an area that works for me. Remember, he already gave so many assists to Messi. "
Alves played for Barcelona in the 2015 final (3-1). Do you want revenge for Juve?
"Everyone really wants to play and we have high expectations. We know the pressure is not on us and we will give our best. It's one of the most important games of my life."
Do you need to score a big goal in Europe?
"It's true that if I score against Barcelona, everyone will see it. Although it's more important to win the tie. Scoring gives you confidence, but giving assists does too much."
Last year you averaged half a goal per game and this season you already have 14. Between you and Higuain, you're dismantling the myth that in Italy it's difficult to score ...
"It's not easy to score goals in Italy. Here the teams keep defending even if you're winning 2-0 [laughs]. It's not like Spain or England. With Gonzalo we always say that it's not enough to score one. We understand each other very well, as if we had been playing together for five years. I interpret his movements and our relationship off the pitch helps us to function better on it. "
You have undoubtedly contributed to Juve's 47 undefeated matches at home.
"Yes, but it's also about people. The stadium is always full, whether in the league or cup, and the opponent gets nervous when we're on top and there's a lot of noise in the stands."
If you score against Barcelona, will you celebrate with the mask?
"Yeah, I will. It's how I've been celebrating my goals since I missed a penalty in the Supercoppa Italiana. I won't change now."
Alves out to remind Barcelona what they are missing
Dani Alves was a serial winner with Barcelona, yet the exuberant Brazilian never felt loved by the Catalan club and on Tuesday will have a chance to show them what they are missing when Juventus host his former side.
The Champions League quarter-final first leg at the Juventus Stadium will be the first time Alves has faced Barca since he left for Turin last summer.
Alves had been one of the architects of Barcelona's dominance in Spanish and European soccer in past years. He won 23 titles over eight seasons at the Nou Camp - including three Champions League trophies and six La Liga titles.
The right back provided 42 assists for Lionel Messi, more than any other player, and notched a total of 100 assists in the league.
Before the club's 2015 Champions League final triumph over Juventus, Messi hailed Alves as the best right back in the world, also saying: "It's very difficult to find a player like him today."
A year later, though, he left the Nou Camp on a free transfer, announcing his departure after the 2015-16 season had ended.
Despite his brilliant understanding with his teammates on the pitch, Alves' flamboyant manner was often viewed as a lack of professionalism by the club's hierarchy.
His sometimes eye-catching social media posts also frequently irked fans. On one occasion last year, he drew criticism from supporters when he posted a video of himself beaten up as a woman and saying Barcelona's elimination from the Champions League was "just a game of football".
In an interview earlier this year with the ABC newspaper Sevilla, Alves was scathing of Barcelona's board.
"The people who run Barcelona have no idea how to treat their players," he said.
"They were very false and ungrateful. They didn't respect me. They only offered me a renewal because of the FIFA transfer ban. That's when I played their game and signed a renewal, which included a clause that allowed me to leave for free a year later. "
"I like feeling loved and as they didn't want me left."
Alves' departure left a gaping hole in the Barcelona team, however. The club opted against signing a replacement, leaving Aleix Vidal and Sergi Roberto to take his place.
Vidal spent much of the season sidelined from the squad by coach Luis Enrique. Shortly after winning his place back in the team in February, the Spaniard sustained a season-ending ankle injury.
Meanwhile, Roberto, originally a holding midfielder, has had an inconsistent season, earning rave reviews in some games but reinforcing the views of his doubters when up against tougher opposition.
Roberto suffered a torrid time in the defeats to Manchester City and Paris St Germain in the Champions League, although he wrote himself into Barcelona folklore by scoring the goal that completed the historic 6-1 win over the French side in the last 16 second leg.
Barcelona appeared to miss the energy and vision of Alves as they floundered to a 2-0 defeat at Malaga on Saturday, a loss which further dented their chances of catching La Liga leaders Real Madrid.
Should the Brazilian engineer Barcelona's elimination from this season's Champions League, they may wish they had shown a little more of the appreciation so craved.