The image of a frustrated Lionel Messi with his hands on his hips in Barcelona's 0-0 Champions League draw in Lyon on Tuesday may reverberate the most around the world, but it is Luis Suarez's form in front of goal that is causing most concern in Catalonia.

Suarez laboured throughout much of the Champions League last 16, first leg in France, although he came as close as anyone to scoring for Barcelona when he fired just wide from a Jordi Alba cutback 20 minutes from time.