THE prospect of trying to figure out a way to halt the Barcelona juggernaut would turn some managers' legs to jelly but Neil Lennon, for now at least, is managing to retain a sense of humour about it all.

"These two [Xavi and Andres Iniesta] are diminutive but giants of the game. [Lionel] Messi is as well. So stop those three and we only have [Cesc] Fabregas, Pedro and [Christian] Tello to look after," he says with a smile.

Lennon describes Celtic's Champions League match in the Camp Nou on Tuesday night as the biggest of his managerial career, by which he doesn't mean the sense of occasion but the tactical and personnel duels he must win if his side are to somehow thwart, or even get the better of, a team viewed by many to be the best in world football right now and possibly of all time.

Lennon and his coaching staff have grown into their roles in the past year or so and the recent victory against Spartak Moscow – Celtic's first Champions League group stage win on the road – was testament to their burgeoning confidence and ability to operate among the elite.

Barcelona take that challenge to a new level, but it is one that Lennon relishes. A deep thinker of the game and someone who never lets a meeting with a managerial great pass by without picking their brains, the Northern Irishman views this as a chance to further enhance his coaching credentials. He is not so arrogant or conceited to feel he does not need any outside help and plans on studying displays by Chelsea and Inter Milan in the Nou Camp in recent seasons to see if he can pick up any pointers.

Those two dogged, defensive performances were perhaps not the most aesthetically pleasing from a neutral's perspective, but there was little doubt they were effective, and it is hard to envisage too many Celtic fans grumbling if their side were to dig out a positive result by similar means.

"Inter didn't win the game, but did enough to get through," said Lennon. "What you need is will and that is what Inter Milan had with Jose Mourinho. You need a good goalkeeper and you need probably a bit of luck as well. Well, a huge slice of luck. Barcelona away? It doesn't get harder than that. But we will do what we can."

Celtic's strong start to the group – they have accrued four points from the first two games – perhaps means there is less pressure on them to take something from the Camp Nou, but that doesn't mean Lennon will travel to Catalonia feeling there is nothing to lose. The Russian side Rubin Kazan were the last team to defeat Barcelona at home in the Champions League three years ago, but their otherwise stellar form will not deter Celtic from having a go.

"Listen, I would never set my team just to sit in," Lennon said. "We will endeavour to have a go because if you go with the idea of sitting in and you go a goal behind after five minutes, then your game plan is out the window and you need to have a Plan B. I always think you need to be flexible and we have got players who can be. I want us to go there and definitely have an avenue where we'll not be sitting in all night and just booting the ball up the pitch and it comes straight back at us. I know that's easier said than done because Barcelona can pin you down for long periods in the game. I'll need pace in the team so I'll look at that."

Stopping Messi, the forward whose genius is matched only by his consistency, will be a sizeable task all in itself. The debate rumbles on as to whether it is he or Cristiano Ronaldo who can lay claim to be the greatest of all time, but Lennon has yet to see a player more impressive than the mercurial Argentine.

"I think we should enjoy the two of them. Ronaldo is getting closer. If you look at the last Clasico it was just Messi versus Ronaldo really. Messi has probably got more excitement in him. Ronaldo has a bit more power, you know, long shots. Messi is more of a dribbler, which we all love.

"That is probably why he is held in affection by more people. It is very difficult to say who is the better of the two. Ronaldo playing for his country has been fantastic. He had a great European Championships. People say Messi doesn't do that on the big stage for his country, but for me-I have not seen anything better than Messi."

Lennon may take some comfort from the fact that he has an unblemished playing record at Tuesday's venue. "I've played twice in the Camp Nou and drawn twice. I don't think there are many players who are undefeated going there. A lot of luck was involved, strong goalkeeping performances and heroic defending at times.

"David Marshall made two or three wonder saves in the first game and in the second game, when we drew 1-1, while they had the bulk of possession – as they always do – I can't remember them having loads of chances. I hope that will be the same on Tuesday."