However, it will still be a major coup by Neil Lennon and his green and white army if they can wrest power from them at Parkhead tonight.
Even shorn of the mercurial talents of the multiple World Player of the Year, and others, including Carles Puyol, Javier Mascherano and Jordi Alba, Barca can still boast a squad which oozes class and a hard-core of Champions League pedigree.
At the risk of delivering a reality check, the cold stats underline the gulf between the squads.
In total, Celtic's players have amassed 131 appearances in the Champions League proper.
Xavi alone has played one more game in the competition, including three successful finals.
Overall, Barcelona's total is 1038 appearances, ensuring that, even with a few fresh faces in their line-up tonight, there will be a solid foundation of experience attempting to stand firm against Lennon's relative rookies.
Of course, a Celtic side with an even lighter Champions League CV proved that such handicaps can be overcome when they defeated Messi and Co. here back in November. They had the help of the now-departed Victor Wanyama and Kelvin Wilson, while even Miku played his part before Tony Watt stole the show with the winning goal.
Now it's their replacements and the rest of class of 2013 who must step up to the mark after a near miss in the San Siro against AC Milan on Match Day One.
If any of the new recruits was still in any doubt what Champions League football is all about, that 2-0 defeat will have put them right.
Now their learning curve is about to become even steeper as they learn what it is like to face Barcelona, and meet the expectation which comes with playing ANYONE at Celtic Park on a big European night.
The past-masters in this discipline, men like Champions League 'veteran' Georgios Samaras, will carry the bulk of the responsibility.
For the Greek international - whose goals have been so important in Celtic's re-emergence as a force in Europe over the past few seasons - this is seen not as a an onus but an honour.
"I enjoy that," said Sami when discussing the fact that, with 13 Champions League Group Stage and last-16 appearances under his belt, along with another 15 in the qualifiers, he is now shouldered with the burden of bringing his wealth of experience to bear.
"It is just me and Brownie who have been here for six seasons, almost. It's good because we know the club, we know the manager and we know exactly what we need to give to the team.
"Of course, we try to help the new guys as well. But all of this is a good feeling. I don't feel any extra pressure, or anything like that. because of this.
"I went through a lot to be in this position. And I feel really proud to have this responsibility, for sure.
"When you have been six years at the club, you play so many games, you need to step up like a good character.
"When things are going wrong, or when things are going well, you need to show to people and say, 'Here I am, you can trust me and together we will go through everything.'"
In the early years after he arrived in January 2008, Samaras often divided opinion on how wise it was to place complete trust in him.
He is now shedding that enigmatic tag, and has clearly put what he has learned to good use, reserving some of his very best performances for the very biggest occasions.
Last season's run to the last 16 owed much to him and his goals. But, as ever, he was happy to play his part for what was a team unaccustomed to dining at the very top table.
In their opening match, against Benfica at Celtic Park, Samaras's absence meant that only captain Brown of the starting XI had ever played in the Group Stage before.
Their tentative approach in the goalless draw exposed their lack of experience, and the fact the manager was very keen not to suffer a home defeat while they were finding out about surviving at this level.
The win in Moscow which followed gave them the self-belief and courage to then head to the Nou Camp ready to give Barcelona a run for their money.
And how they did before finally conceding a late goal and a point they richly deserved.
The victories at Parkhead against Barca then Spartak Moscow which followed took their points to 10, and carried them with the La Liga giants into the last 16.
"What we got from all the journey in last season's Champions League was experience, for sure, but also belief," said Sami.
"The players who were experiencing it for the first time saw the Champions League and could feel Celtic Park on that special night and had belief in the team and in themselves to go and do great things.
"What we did last season was great, to get through the Group Stage and play in the last 16."
Now the mountain stands before them again, and conquering it will be every bit as difficult, though Samaras believes they have already achieved much just to get past base camp.
He explained: "Already we have done a lot this year, getting through three qualification rounds, including a great game against Shakhter Karagandy to overturn being 2-0 down from the first leg in Kazakhstan.
"Our realistic target was to get into the Group Stage. Now we are playing against great teams, and what will happen, we don't really know.
"We will just try to enjoy the games. And, if we go through, that will be amazing."
That's the long-term aim. The short-term target is to avoid going into the double-header against Ajax still pointless.
By the time they went into the head-to-head with Barcelona in Match Day Three and Four last year, they already had a win and a draw under their belt.
Defeat tonight would leave them four points behind that mark. Not that this prosect has an unsettling effect on the club's laid-back Player of the Year.
"We always go out to try and win our games," is Sami's simple viewpoint. "If we don't win against Barcelona, it would be excellent to take just one point, then we can go into the two games against Ajax with something in our hands."