To Athletic Bilbao, the UEFA Champions League anthem played at San Mamés on September 16th, 2025, at 04:45 PM UTC will have more meaning than just the start of another football match, it will have more value than the previous 82 years of wait and will showcase Athletic Bilbao’s finally returned European glory. The Basque Giant makes its return to the UCL after eleven years, and with that comes one of the most difficult challenges one can surmount: UCL matches. In recent years Arteta’s Arsenal has definitely become one of the more consistent teams, which makes this duel even more interesting.

For Arsenal, the fixture represents another step in their development under Arteta, having taken them from a middle-of-the-pack Premier League side to their current standing as an elite outfit featuring in European football's premier competition. Arsenal have progressed to the quarter-finals in the 2023-24 season and the semi-finals for the 2024-25 season and are keen to finally conquer the one competition that keeps eluding them.

But San Mamés—dubbed “La Catedral” (The Cathedral)—isn't just any destination. It's a boiling pit of passion, history, and identity. Athletic Bilbao, whose insistence on using Basque-only players has shaped a strong sense of identity for them, will be leaning into that identity, as well as the raucous support of their vociferous fans and the bright spark of players like Nico Williams and Oihan Sancet, to disrupt Arsenal's flow of play. 

This isn't a mere fixture. This is tradition vs. ambition. Heritage vs. evolution. The Lions vs. The Gunners. 

For the better part of 2 decades, Arsenal's story in Europe has been one of nearly moments and heartbreaking disappointments. The memory of their loss to Barcelona in the 2006 final remains with their fans, and repeated eliminations at the hands of Europe’s heavyweights became a common occurrence under Arsène Wenger. 

Today, though, Arteta has restored a sense of belief in a club that in the last 2 campaigns has matured into real contenders:

Arteta has assembled a balanced squad of youth and experience, along with flair and tactical flexibility. The likes of Martín Zubimendi, Eberechi Eze, and Viktor Gyökeres have added quality and depth, and established stars such as Martin Ødegaard and Bukayo Saka continue to drive the team forward.

Arsenal's stumble on the opener against Liverpool in the Premier League may have raised overseas eyebrows, but their impressive 3-0 win against Nottingham Forest at the weekend—inspired by a brace from Zubimendi—showed they still have the requisite strength. The Champions League is a different animal in many ways, and they know that such away nights will define their campaign.

For Athletic Bilbao, this is not just another fixture—it is a celebration of persistence and identity. It's been eight years since their last Champions’ League group stage campaign, when they exited at the hands of Porto, Shakhtar, and BATE Borisov. Since then, they have been the forgotten men behind Spain's big three, with some moments in the Europa League, but always battling to re-earn allegiance within La Liga's institutional elite.

Athletic have a swagger again under Ernesto Valverde. A fourth-place finish in La Liga last season could only be considered a triumph. It got them back into the Champions League, and they come here not as underdogs happy to be in the competition but as a club that wants to show they can compete with the best.

San Mamés will be their fortress. It is an atmosphere like no other that has broken many visiting teams. For Arsenal, it is both a challenge and a rite of passage.

This is the first competitive meeting between Arsenal and Athletic Bilbao.

The stage is set for a fascinating tactical contest.

This match will be defined by styles:

Valverde is pragmatic but bold. Expect a 4-2-3-1 formation, intending to counter with quick transitions.

Arteta sees a 4-3-3 based on possession and control.

Expect Arsenal to provide the majority of possession (~60%), but every time Arsenal breaks their press, Athletic will look to counter quickly.

Arsenal, with their greater squad depth and prior European experience, should provide the edge for them, but ultimately Bilbao will get a goal in front of their fans.

Expect a battle, an emotional one. Bilbao will make them sweat but can probably test Arsenal's European maturity.

For Athletic Bilbao, the return to the Champions League is a tale of endurance, tradition, and pride. Regardless if they win or lose, San Mamés will roar like it hasn't in a decade. For Arsenal, it is another phase in their journey from “nearly men” to serious challengers on the European scene.