#3 Inter Milan (3 games)
Barcelona vs Inter Milan was one of the most vital games ever played in modern football. It was in this fixture when Jose Mourinho laid out the blueprint to stop Pep Guardiola's men who were the best football team back in 2010.
The Catalans met Inter 4 times in season 2009-10, twice in the group stage and twice in the semi-finals. However, Messi was far from being at his imperious best in 3 out of the 4 games he faced them.
The resilient Inter defence successfully subdued the Ballon d'Or winner, who failed to find the net in 270 minutes in 3 games against them. The Nerazzurri knocked out the Catalans with an aggregate score of 3-2, eventually beating Bayern Munich in the finals to lift the title.
The football world will once again witness Ernesto Valverde's Barcelona coming up against Inter Milan this season in the Champions League group stage. However, given his recent arm injury against Sevilla, Lionel Messi will probably be out of both the group stage clashes against the Nerazzurri.