Selecting Gerard Pique in the starting line-up after three months out through injury was a big gamble from Ronald Koeman.
At the age of 34 and coming back from a long absence, Pique obviously lacks pace – and it only took 50 seconds for Kylian Mbappe to expose that by running past the Barca back line for a chance he could have made more of.
Pique’s presence means that Barca defend deeper, as he doesn’t want to leave space behind and therefore drags his back four closer to their own goal.
This gave PSG room to play around the edge of the penalty area, something they exploited to create plenty of chances.
But Pique was by no means Barca’s only defensive problem, and the second half in particular very clearly exposed the team’s deep structural flaws.
Specifically, the transition between attack and defence continues to be a major weak point, especially against an opponent boasting the athleticism of PSG. The first point of Barca being out-played by the French team is that they were out-run, with the massive amount of space between their attack and defence giving PSG an open invitation to run riot.
Playing such an open style with a deep-lying defence just invites trouble, even more so when the midfield anchor is Sergio Busquets, who sadly looks physically out of his depth at this level now.
PSG’s superiority was plain to see, particularly during the early stages of the second half when they created plenty of chances to move into a 2-1 lead which was eventually inevitable.
So it has to be regarded as a major failure by Koeman that he did nothing to intervene.
The Barca boss did not make any substitutions until the 71st minute, by which time PSG were 3-1 up and the tie already effectively over.
And although Koeman has done a generally decent job in difficult circumstances this season, his ability to manage games against top-quality opposition remains highly questionable.