Barcelona's preparations for Sunday's highly anticipated El Clásico against Real Madrid have suffered a significant setback after Spanish international Dani Olmo was ruled out for approximately one month through injury. The development comes at an uncomfortable moment for Hansi Flick, whose side are attempting to recover from a painful Champions League defeat while preparing for one of the most demanding fixtures on the Spanish football calendar.

The Catalan giants confirmed on Wednesday, 21 October, that medical examinations had revealed an injury to Olmo's left adductor muscle. The midfielder sustained the problem following a collision during Barcelona's 4-2 defeat to Paris Saint-Germain at the Parc des Princes on Tuesday evening. He was forced to leave the pitch after just 27 minutes, with Fermín López coming on as his replacement.

Losing Olmo would be concerning under ordinary circumstances, but the timing makes the situation particularly difficult for Barcelona. The Spanish midfielder offers creativity, intelligent movement and the ability to operate between opposition defensive lines. His technical qualities are especially valuable in matches where Barcelona must overcome opponents capable of applying intense pressure and restricting space in midfield.

Against Real Madrid, those qualities could have provided Flick with additional attacking flexibility. Instead, the German tactician must reconsider his midfield options at a time when Barcelona's squad is already dealing with several fitness concerns.

The injury also comes immediately after Barcelona suffered their first defeat of the season. Their encounter with defending European champions PSG exposed weaknesses that Flick will need to address before Sunday's showdown. Despite producing moments of attacking quality, Barcelona struggled to contain the French side's attacking movements and eventually conceded twice late in the contest.

What makes the defeat particularly concerning is the manner in which Barcelona appeared increasingly vulnerable as the match progressed. Their attacking ambition created opportunities, but it also left spaces that PSG exploited effectively. Against a Real Madrid side possessing considerable attacking quality, maintaining the right balance between defensive discipline and offensive aggression will be essential.

Flick therefore faces two interconnected challenges. He must find a suitable replacement for Olmo while ensuring his team does not repeat the defensive mistakes that contributed to their European defeat.

Fermín López represents one possible solution. His energy, willingness to attack spaces and ability to contribute offensively could provide Barcelona with a different midfield dimension. However, replacing Olmo is not simply a matter of selecting another technically gifted footballer. Flick must consider how the change affects Barcelona's pressing structure, ball progression and attacking combinations.

There are also questions surrounding the team's physical condition. Barcelona have been navigating a demanding fixture schedule, and the defeat in Paris raised concerns about fatigue. Reports suggest that several players, including Lamine Yamal, Pedri and Fermín López, participated in additional training despite having been granted time off.

Such commitment reflects the importance of the approaching encounter, although managing player fitness will be equally important as Barcelona attempt to avoid further injuries.

Nevertheless, the Catalan club still have reasons for optimism. Their impressive domestic form demonstrates that the PSG defeat should not automatically be interpreted as evidence of a wider collapse. Barcelona entered the European encounter having enjoyed an exceptional start to the campaign, and one disappointing result does not erase the progress achieved under Flick.

Sunday's meeting with Real Madrid will therefore provide an important examination of Barcelona's resilience. A convincing performance would demonstrate their ability to respond positively to adversity, while another disappointing result could intensify scrutiny of the team's defensive organisation and squad depth.

For Flick, the immediate priority is clear: restore confidence, adjust his midfield and prepare his players for the intensity of Spanish football's biggest rivalry.

Olmo's absence is undoubtedly a setback, but the greater question is whether Barcelona can adapt quickly enough to overcome it.

With El Clásico approaching, the Catalan giants have little time to find the answer.