For so many years their strongest sector, the Catalans are no longer the same side in the centre of the park these days. So where has it gone wrong?
Many called it the greatest midfield in history. The trio of Xavi, Andres Iniesta and Sergio Busquets took Barcelona to new heights under Pep Guardiola between 2008 and 2012. Those days, however, are long gone - and the Blaugrana rely much more on their front three now.
Iniesta and Busquets are still at Camp Nou, of course, but Barcelona's style of play has changed in recent years - even before Xavi left the club to move to Qatar at the end of the 2014-15 season.
With Iniesta sidelined through injury, Busquets below his best and Ivan Rakitic off colour as well, Barca's midfield has appeared ordinary in recent matches, leaving many fans frustrated that their team has lost some of its identity and some of the spectacular style that made them so successful.
In reality, the decline has been gradual. The arrival of Cesc Fabregas in 2011 saw Guardiola make some tactical tweaks in his final season in charge, playing the former Arsenal captain as a false nine in order to fit him in the team along with Xavi, Iniesta and Busquets.
That halted the rise of another La Masia graduate, Thiago Alcantara, and he was ultimately allowed to leave in 2013 because his path to the first team was blocked by Cesc. At that point, it seemed like an embarrassment of riches. But a year later, Fabregas left as well.
That was Luis Enrique's decision. The current Barca boss is keen on a more direct philosophy and Rakitic arrived to make the team more aggressive, with faster transitions and greater athleticism.
It worked well. With Iniesta still sparkling and Xavi an option from the bench when Barca wanted to revert back to their patient passing philosophy in order to keep the ball and frustrate rivals, it was in many ways the best of both worlds.
Barca won the treble that season, with Rakitic and fellow summer signing Luis Suarez fundamental to their success. Xavi, however, had also played his part, while Iniesta was Man of the Match in the Champions League final win over Juventus.
But Xavi left the club that summer and the man signed as his replacement, Arda Turan, took time to settle after sitting out the first six months due to the transfer ban handed to the club for irregularities in the signing of young players. Even now, he has not made the desired impact and has looked more effective further forward - where Barca are already well stocked.
Following Xavi's departure, Lionel Messi has often been the man providing the creative spark, dropping deep to stamp his authority on games and shining in something of a playmaker role as well as scoring goals himself. Against rivals who set up to press Barca, though, even the Argentine's influence is limited at times - and that is where the midfield should come in.
However, Barca's midfield has been overrun at times this season. The way the team plays these days is also less suited to Busquets, who's carried a niggling fitness problem and is unsuited to covering great distances, but to astute positional play. Perhaps that explains his dip in form over the past few months.
On top of that, Andre Gomes has struggled to adapt following his move from Valencia in the summer. Signed as a long-term replacement and also cover for Iniesta, the Portuguese has yet to score and has not convinced either. His best game was away to Manchester City in the Champions League, yet that ended in defeat and included a squandered chance that struck the bar when he really should have hit the back of the net.
Some supporters were keen for Barca to utilise Sergi Samper instead of signing Gomes, but Luis Enrique sent the homegrown midfielder on loan to Granada where he has shown he is not ready to play atthe highest level just yet. Will he be in future? Many at the Catalan club have their doubts. He has the talent, but perhaps not the personality or attitude to succeed at Camp Nou.
In the meantime, one homegrown midfielder who is impressing at Barca is Sergi Roberto. However, he is being used at right-back because Aleix Vidal is not considered a viable option following the departure of Dani Alves in the summer. But the Catalan's performance in last season's 4-0 win away to Real Madrid as an outside right who doubled up in midfield (with Messi on the bench as he returned from injury) showed just how useful he can be further forward.
With both Busquets and Rakitic off form and carrying knocks, Barca will be delighted to welcome back Iniesta for the Clasico against Madrid on Saturday. However, the Spain midfielder will be 33 in May and it is time to start thinking about the future as well.
Denis Suarez, still only 22, was brought back with that in mind, while Carles Alena (who scored away to Hercules in the Copa del Rey on Wednesday) is another talent, although there is no guarantee he will reach the level required for the first team.
Over at Real Madrid, meanwhile, there are several players who would have suited Barcelona, namely Luka Modric, Toni Kroos and Isco - technically gifted footballers who could have picked up the baton in midfield at the Catalan club. And on Saturday, some fans of the Blaugrana may just cast an envious eye at their rivals' array of talent - much of it in reserve.
In any case, Luis Enrique will now be charged with sorting out his side's current problems - and Barca still possess plenty of talent. The Asturian appears more concerned with results and the present than with planning ahead, however, and the midfield malaise is something that will need to be addressed either by the 46-year-old or by his successor.
Because Barca have lost a part of what made them so great - and their famous forward line cannot paper over the cracks forever.