Given that at the time of writing FC Barcelona lead the Spanish top flight – after their best-ever start to a Liga season – and set the pace in UEFA Champions League Group G, this is no time to start talking about even a mini-crisis at the Camp Nou. But a blip, maybe.
There is no sense in avoiding the fact that Celtic FC beating the FIFA Club World Cup champions, and with more merit than the 2-1 scoreline suggests, caused seismic reactions across European football – romance lives on.
It was not simply that there were no shrewd judges who suspected a home win might be on the cards. The response of both coaches and each set of players following Barcelona's narrow win in the preceding match made it clear that all the participants assessed the night at Celtic Park as a potential banana skin for the Catalan side.
What really rang minor alarm bells was Barça's defending in Glasgow and the sensation that the performance echoed that astonishing night in April when ten-man Chelsea FC drew in Barcelona to reach the Munich final.
The link is simple: the Blaugrana, with even more lavish possession stats than normal, created oodles of chances but failed to convert superiority into the necessary result. A nod to FC Internazionale Milano fans while we are at it – both aforementioned games evoke that electric night in 2010 when Barça were also unable, by a single goal, to turn dominance and a man advantage into a passage to the Madrid final.
However, Sergio Busquets, absent from the two Celtic matches but restored for the long daunting trip to Moscow next Tuesday, articulated the root of the problem: it is not scoring, but defending. "We've conceded too many goals which we should have been able to avoid," the midfielder said.
Recurrent injuries to Gerard Piqué, Carles Puyol and Daniel Alves offer at least a partial explanation, yet it is a trend which coach Tito Vilanova will want to end promptly. Prior to facing FC Spartak Moskva, who were the earliest team to indicate there may be cracks in the Azulgrana defensive structure by scoring twice at the Camp Nou on matchday one, Barça have shipped five goals in Group G.
Just as an index, when Barcelona won the UEFA Champions League in 2006, 2009 and 2011, they had, respectively, conceded once, three times and three times by this stage. Indeed in 2005/06, Frank Rijkaard's team were breached just five times all competition.
The already interesting visit to Russia holds further intrigue because of the fact many of Vilanova's squad flew over 16,100km to Panama for Spain's midweek friendly international. The dreaded jet-lag and mental tiredness is what all top teams fear the most.
Domestically, too, the startling sight of Vilanova's charges playing majestically in attack at RC Deportivo La Coruña (5-4), Rayo Vallecano de Madrid (5-0) and RCD Mallorca (4-2) – yet shipping six goals in the process is a sign there is fine-tuning to be done. However, this is where those who suddenly advocate that, following the lack of a clinical touch in Glasgow, Barcelona have to develop a Plan B miss the point.
"We play so many teams who defend like Celtic did, home and away, and we win 95% of those matches," said Vilanova. "We don't need a Plan B, we just need to make Plan A work better," added Alves. They are right. When Piqué, Puyol and, hope against hope, Éric Abidal are back and functioning properly in Vilanova's back line, Barcelona are credible contenders for a treble this term.
If not, then the 'we'll-score-more-than-you' philosophy which has served them well so far might not be sufficiently mean-eyed to steer them to their fourth European crown in eight seasons.
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