GEORGIOS SAMARAS has scored in every one of Celtic's last four away wins in Europe – most recently the winner against Spartak in Moscow – and this underlines his importance to the Bhoys when they hit the road.
However, it is not just his scoring contribution which makes him the fulcrum around which Celtic's fortune revolves.
His ability to win the ball in the air in both penalty areas, and his capacity to carry the ball far upfield, allowing the defence to re-organise and enjoy some much-needed respite, is vital to the way the team performs.
Neil Lennon was quick to recognise his potential and importance, and this is why he was left out of the side at Paisley on Saturday because the manager was not prepared to risk losing him for the Nou Camp.
WANYAMA says ALISON McCONNELL
TOMORROW night will be a game in which Celtic can expect to spend much of the game chasing shadows as Barcelona inevitably control possession.
To that end, it will be someone like Victor Wanyama who could be the key man for Neil Lennon's side.
The Kenyan internationalist has shown a level of promise at this stage and it will be his ability as a defensive midfielder that could be pivotal to Celtic's game plan.
He is capable of breaking up the play, of retaining possession and of maintaining his workrate throughout the 90 minutes.
If Scott Brown fails to make kick-off because of his hip injury, Wanyama's role would become particularly crucial.
However, he needs to be wary of rash challenges, since an early caution could leave him at risk of collecting a second yellow or giving away a set-piece in a dangerous area.