Neil Lennon has twice played a part in thwarting Barcelona in front of their home crowd, but if he should achieve the feat a third time this evening, it will be the outstanding accomplishment of his fledgling career as Celtic manager.
Lennon, now 41, was the combative heart of Martin O'Neill's Hoops team when they travelled to the Nou Camp twice in the space of eight months in 2004 and departed with a draw in each case -- first in the UEFA Cup and then, as now, in the Champions League group stage.
"It was the pre-Messi days," Lennon recalled yesterday. "Xavi was already in the side but he was young and Iniesta was on the cusp of the squad.
"Since then, those three have been key to why Barca have been so successful. Put those three in any team and I suspect they would turn them into world beaters.
"Back in the day, Ronaldinho was World Player of the Year. Then there was Eto'o, Deco, Giuly and Henrik Larsson. It was a Rijkaard team and they were pretty special but they hadn't really reached the heights when we played them.
"It was the following year they won the Champions League -- the springboard for all the success they have had since -- but this Barcelona team is two or three gears better than anything I have seen before. The challenge facing my team is bigger than it was back then."
The Celtic side of 2004 was also a step up from the current Parkhead squad, in value and achievement. They took Jose Mourinho's Porto to extra-time in the UEFA Cup final in Seville in 2003, and O'Neill could pay salaries which went out of reach for Celtic some time ago.
Invited yesterday to contemplate the even wider gulf between the resources available to him and those of his Barca counterpart, Tito Vilanova, Lennon immediately focused on Lionel Messi. At the pre-match press conference he suggested that the mercurial Argentinian, like every other footballer, depended on good supply.
Afterwards, though, the Celtic manager was rhapsodic about Messi's individual capabilities, which he witnessed first hand on Saturday night when Barca -- reduced to 10 men -- overcame Deportivo 5-4. "He basically made the two opposing centre-halves redundant," said Lennon.
"He just walks around as the ball is being popped about and lets everyone else deal with it. Then, all of a sudden, boom! He comes alive.
"He just has that burst of pace to get away from people. One minute he looks as if he's not interested, the next thing he'll drop a shoulder and he's away. But my centre-halves will have to be so mindful, not just of Messi, but also of players around him like Fabregas and Iniesta.
"We can talk about them all night -- how we go about stopping them -- but they come at you in so many different ways that it's near enough impossible."
Nevertheless, Lennon will attempt to insulate his players from the radiance of Barca's genius, even as the teams prepare to walk out.
Celtic have been told not to negotiate shirt swaps in the tunnel.
"Well, I can't really stop them because I won't be in the tunnel when the teams walk out, but I just want them to try to focus on getting a foothold on the game at some stage," said Lennon. "People do all this, 'There he is, look at Xavi.' And it's, 'Can I have your shirt after the game?'
"But that's not what it's about. These guys will eat you alive if you give them half a chance. They will rip you to shreds. Barcelona make great teams look ordinary. It's a totally different set-up for me as a coach. The normal instincts of the players will be curtailed, not by choice -- just by the sheer force of the players they are going to come up against.
"There is anxiety there. I've thought about nothing else.
"We can maybe affect Barcelona at set-pieces but our delivery has to be right. And you have to hope we get a f**king set-piece in the game."
Yet, for all of the fear, Celtic do have a modicum of hope.
They go into this match unbeaten in six European ties, with five wins and four clean sheets.
They are also the first Celtic players to win away from home in the group stage in 21 attempts. Barca, too, are wary of their threat.
Manager Vilanova was quizzed repeatedly yesterday about the defensive crisis he has on his hands with Gerard Pique joining Daniel Alves, Carles Puyol and Eric Abidal on the sidelines while midfielder Sergio Busquets is suspended.
After conceding four goals in a 5-4 win over Deportivo La Coruna at the weekend, midfielders Alex Song and Javier Mascherano look set to form a makeshift central defence again.
"All Champions League games are complicated and I am worried because Celtic are very fast up front and they proved it against Spartak. They play good, counter-attacking football so we know they are dangerous," said Vilanova. "They are also good in the air and so I am really worried about that."
Barcelona v Celtic
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