If the performance of their defence against Valencia is the barometer which we should measure them by then the Catalans are in trouble.
They were awful in the first half against Los Che and Barca only ended up keeping a clean sheet thanks to the heroics, again, of Claudio Bravo.
If there was any rejoicing at the return of Dani Alves, then that would've been quickly dispelled. The returning Brazilian wasn't really at the races.
His performance was so poor that you have to wonder if all of the transfer speculation is getting to him. How else do you explain his lack of concentration and application?
When he plays like this, it's no wonder that the club have been slow in offering him a new deal. Martin Montoya and Douglas aren't the best replacements, granted, but neither is Alves the answer in the right-back slot on this form.
They've only themselves to blame, of course, and the deal-makers at the club shouldn't leave Cules having to put up with this make-do-and-mend scenario.
If Laurent Blanc and his players have watched a re-run of Saturday's game, one of the first conclusions they will draw is if PSG target Alves during the match at Camp Nou, then they will profit at some point.
In fact, it would be a huge surprise if they didn't particularly target Alves anyway. During this campaign his swashbuckling manoeuvres down the right channel have left Barca light in defence on numerous occasions and in trouble against the better sides in La Liga or the Champions League as a result.
Blanc recently told reporters, as detailed by Miles Chambers of Goal.com, that no bid had been made to purchase Alves. On this form it's a wise move.
Jeremy Mathieu at least emerges with some credit. The ex-Valencia man looked comfortable for the most part, both centrally and as left-back after Adriano was taken off at half-time.
Gerard Pique, too, was diligent if a little more nervous than he has been of late. He'll certainly feel aggrieved at the awarding of a penalty to the visitors when replays showed he did little wrong. However, there can be no such slip ups in the Champions League.
It's time for all of Barca's defence to stand tall and Sergio Busquets has to be included in that.
Caught out of position on occasion in Paris, he started the game against Valencia with a super ball to Lionel Messi that allowed the Argentinian to feed Luis Suarez for the opener. But what did he do for the next 44 minutes?
Even taking into account his improvement in the second period, he and others are going to be given the sternest examination of their credentials by PSG. If they are not on their mettle from the get-go, as against Valencia, then there is every chance that the unthinkable could happen.
The air of expectancy that will naturally be permeating discussions in the locale needs to be reined in just a little. An early goal from the French champions could well unsettle a brittle back line.
A 3-1 lead is healthy, yes, but not insurmountable.