Two weeks ago Celtic took most of the plaudits for a brave show in the Nou Camp before losing out to a Jordi Alba strike in the fourth minute of stoppage time.
That display, coupled with a 3-2 win away to Spartak Moscow, has created expectations that the Hoops can take a point from the most revered and feared side in the game.
"Barcelona might think, 'We really have to turn it on and put this team in their place'," claimed a worried Lennon last night.
"That's what I'm thinking given that we're playing them so soon after the game at their place.
"It could also be great motivation for us, that the way that game ended is still fresh in the mind and still raw with the players.
"They put so much into the last game and got nothing from it so they want to go one better this time but I'd never be blasé against this Barca side," he added.
"We're tight up against it. I watched them away against Benfica and half an hour into the game they were one up with 70 per cent of the possession. That's exactly what they do to teams.
"They pass it so well and have complete trust and faith in one another, the way they take the ball under pressure and just know where the other player is. That's born out of having quality players.
"Our players are more aware of what they're going to come up against now, having played them. It's everyone's dream to play against Barcelona. That dream is a reality, it's hard work, it's concentration, leg work and discipline."
Lennon added: "I'm trying not to be too negative, but if you go out and say, 'right let's press them' they will pick you off. They will miss the midfield out and just go at you from wide areas.
"They are the best football team in the world and they have been for a considerable time."