The Parkhead men trail their star-studded hosts at the top of Group G by two points after two games but few expect an away win, even though Barca coach Tito Vilanova has something of a defensive crisis on his hands with Daniel Alves, Carlos Puyol, Gerard Pique and Eric Abidal all expected to be missing.
Lennon acknowledged the magnitude of the task in hand, but said: "It is exciting times for the players and the club and the supporters as well. But we are not here for a holiday. We are not here for the tourist attractions. We are here to play football. We are going to be in for a tough 90 minutes but we want Barcelona to be in for a tough 90 minutes."
He added: "We need character and mental strength and allied to that the players need to play at the peak of their abilities to overcome what is probably the best team in the world at the minute."
Lennon, however, admits Celtic's first away win in the Champions League against Spartak Moscow in Russia earlier in the month, where Georgios Samaras headed a late winner in the 3-2 victory, has taken some of the pressure off his side.
He said: "There is always pressure going into any game but what we have done is give ourselves a nice cushion, a platform. Maybe we didn't visualise getting a result in Moscow but this is the ultimate test, away from home against Barcelona. We haven't really budgeted for anything out of this game but who knows?
"The players are young and fearless. There is a bit of naivety about them at times but there is plenty of international experience and we saw that in Moscow."
Lennon watched Lionel Messi score a hat-trick for Barcelona in their 5-4 win over against Deportivo La Coruna at the weekend. The former Celtic skipper, however, believes the Argentinean is only one, albeit the most potent, of the threats his side will face.
"You can man mark but he still finds a way," he continued. "It was a privilege to watch him live for the first time on Saturday night, he was exceptional."
Scott Brown (hip), James Forrest (groin), Georgios Samaras (elbow) and Kris Commons (hamstring) returned to the squad after missing Saturday's 5-0 Clydesdale Bank Premier League win over St Mirren in Paisley. Defenders Adam Matthews and Kelvin Wilson picked up respective knee and calf complaints during the win over the Buddies and will also be assessed at training.
Source: PA
Source: PA