With Atletico Madrid already through, Celtic are vying with Udinese to join them in the knockout stages, although the results of Group I are subject to the verdict from the Court of Arbitration for Sport in the case between FC Sion and UEFA.

Udinese are currently three points ahead of Celtic, but the Bhoys would go through on head-to-head record with victory in Italy - and Lennon is in a determined mood.

Lennon said on the club's official website, www.celticfc.net: "We do have to win it. A draw or a defeat is no good to us.

"We have to be very respectful of the opposition who, as we speak, are top of Serie A so they are obviously an excellent side.

"I think we can set up to be a little bit more adventurous with our own approach.

"The pressure is off and the players can go and hopefully express themselves and do the club justice."

Celtic are in a rich vein of form domestically, having won their past six Clydesdale Bank Premier League games, scoring 13 times in the process.

But Lennon knows his side must find a way past goalkeeper Samir Handanovic and to stop Italy striker Antonio Di Natale to advance.

He added: "They are very strong in midfield. They have great strength, athleticism and quality - and counter-attack very quickly.

"Added to that they have a brilliant goalkeeper, I think he is one of the best in the world.

"I remember him from the last World Cup for Slovenia he was fantastic, and he pulled off three or four unbelievable saves here in the home game.

"He gives a great foundation for them to build on. And with people like Di Natale in the team, there's always a goal threat at the other end.

"They are very well-organised but skilful into the bargain."