4) Barcelona
Far from a vintage Barcelona side, but with Lionel Messi breaking records left, right and centre at the moment and looking back to his best, Barcelona have to be considered as slight outsiders among Europe’s elite just now. Luis Enrique is new to a job of this size and the jury is still out on him as Barca boss, but he has the players at his disposal to make a mark in this competition. Defence is a weakness and will surely be exposed later on as they face tougher sides, but the Catalan giants will be looking to make up for their disappointing exits in the last few seasons, with a narrow defeat to Atletico Madrid last year and a thrashing at the hands of Bayern Munich the year before.