The trip, captured by cameras from the Spanish programme El Chiringuito, followed a meeting with Barcelona's head coach Hansi Flick, hinting at serious transfer talks.
Accompanying Deco were Bojan Krkic, the club's football area coordinator, and Alejandro Echevarría, a close advisor to Barcelona president Joan Laporta.
Deco remained tight-lipped when pressed by reporters, sidestepping questions such as, "Is the Nico Williams deal done?" and "Is Nico Williams Barcelona's top target?" His silence only fuelled speculation about the 22-year-old Spaniard's future.
Barcelona president Joan Laporta added to the excitement, hinting at big moves in the transfer market. "We are close to finalising one signing, and we could make another that has us thrilled," Laporta said during a recent address at the club's Senate meeting, where he reviewed the season's progress.
Williams, who has a contract with Athletic Bilbao until 2027 and a release clause of 60 million euros, has emerged as a prime target for Barcelona. The winger's flair and versatility have also caught the eye of other European giants, with Bayern Munich reportedly monitoring his situation.
Barcelona have also been linked with Liverpool's Luis Diaz, Manchester United's Marcus Rashford, and AC Milan's Rafael Leao, but Williams' recent form and youth make him a standout choice.
Just days ago, Barcelona's rising star Lamine Yamal shared a photo with Williams, further stoking transfer rumours among fans.
As the transfer window heats up, Barcelona's pursuit of Williams signals their intent to bolster their attacking options. Whether Deco's Ibiza trip clinches the deal remains to be seen, but the Blaugrana are clearly aiming high.