In one of the most exciting matches of the UEFA Champions League Matchday 1, Athletic Bilbao will face Arsenal on Tuesday, September 16, 2025, at the iconic Estadio San Mames in Bilbao, Spain.
This Champions League Phase clash between Athletic Bilbao and Arsenal holds particular significance for both clubs’ European ambitions.
The new format, which runs from September 16, 2025, to January 28, 2026, features 36 teams in a single league table, with each side playing eight opponents (four home and four away).
A three-point win at San Mamés could prove decisive in the race for knockout-stage qualification.
Tactically, this will be a fascinating duel between two managers in Ernesto Valverde and Mikel Arteta.
For Bilbao, the match marks a highly anticipated return to Europe’s elite stage, while Arsenal arrive as one of England’s most established contenders.
Both sides have started their domestic campaigns positively, and victory here would prove a major step towards making a deep run in the 2025/26 UEFA Champions League.
Team Analysis and Current Form
Athletic Bilbao
Athletic Bilbao have come into this match with a mixed record in their recent La Liga matches.
In terms of their current form, they suffered a disappointing 1-0 home defeat to Alaves on September 13, 2025, which followed a 2-1 away win against Real Betis on August 31.
Previous results include a 1-0 win over Rayo Vallecano and a 3-2 win over Sevilla, both at San Mamés, which showcase their strong home form.
However, the search results indicate that Athletic Bilbao “have not scored in their last 2 matches,” suggesting that there could be some offensive struggles in this crucial Champions League clash.
Athletic typically combine high-intensity pressing with direct attacking play that maximises their physical advantages.
Their traditional 4-2-3-1 formation focuses on winning second ball and creating chances through wide areas, with their full-backs providing crucial width in attack.
The team’s defensive organisation has generally been strong, although recent goalless performances point to some attacking inefficiencies that manager Ernesto Valverde will need to address before facing Arsenal’s disciplined backline.
Arsenal
Arsenal are likely to be in impressive form heading into this Champions League tie, having won 3-0 against Nottingham Forest in the Premier League on September 13, 2025.
This result follows a narrow 1-0 away defeat to Liverpool on August 31, which has included impressive performances that included a 5-0 thrashing of Leeds United and a 1-0 away win against Manchester United.
The Gunners have displayed both attacking firepower and defensive tenacity in equal measure, with their new signings making significant contributions.
Under Mikel Arteta, Arsenal have developed a possession-dominant style that focuses on controlled build-up play and tactical pressure triggers.
Their fluid 4-3-3 formation gives their attacking midfielders creative freedom while maintaining structural discipline.
The recent addition of Victor Gyokeres has added a new dimension to their attack, providing a physical presence and clinical finishing ability.
Team News and Predicted Lineups
Athletic Bilbao Team News:
Winger Nico Williams is racing against time to be fit for the match due to a moderate hip injury sustained during international duty.
He missed Bilbao’s recent league defeat to Alavés, and manager Ernesto Valverde has not provided a guaranteed return date, stating, “It will depend on how his injury progresses”.
Defender Unai Egiluz is confirmed unavailable. Although Aymeric Laporte’s return to Spain has boosted morale, he will not feature in this fixture.
With Williams potentially out, Valverde may rely on Álex Berenguer or Iñaki Williams (Nico’s brother) to lead the attack alongside Gorka Guruzeta.
The team is expected to emphasize quick transitions and width to exploit Arsenal’s defensive setup.
Athletic Bilbao Predicted Lineups (4-2-3-1): Unai Simón; Jesús Areso, Dani Vivian, Aitor Paredes, Yuri Berchiche; Iñigo Ruiz de Galarreta, Mikel Jauregizar; Iñaki Williams, Oihan Sancet, Álex Berenguer; Gorka Guruzeta.
Arsenal Team News:
Arsenal are facing significant absences, including Bukayo Saka (injury details not specified), William Saliba, and Gabriel Jesus.
Summer arrivals Victor Gyokeres (striker) and Eberechi Aje (attacking midfielder) are expected to start.
Gyokeres scored his first goal for Arsenal in a pre-season friendly against Bilbao and recently scored again in a 3-0 Premier League win over Nottingham Forest.
The likes of Noni Maduke and Martin Zubimendi (who scored twice against Nottingham Forest) are likely to feature prominently in Mikel Arteta’s squad.
Arsenal Predicted Lineups (4-3-3): David Raya; Ben White, Cristhian Mosquera, Gabriel Magalhães, Jurriën Timber; Martín Zubimendi, Declan Rice, Martin Ødegaard; Noni Madueke, Eberechi Eze, Viktor Gyökeres.
Match Prediction and Key Factors
This Champions League clash presents a classic clash of styles that makes European football so fascinating. A number of key factors will likely determine the outcome.
Athletic Bilbao’s impressive record at San Mames cannot be underestimated. Their defensive organisation will make scoring opportunities rare.
Arsenal’s strong recent goal-scoring form could give them a narrow advantage in this fixture, but breaking down Athletic’s defence at San Mames is one of the most challenging tasks in European football.
Both managers are known for their tactical adaptability during matches. Given these factors, a closely contested match is expected.
Predicted Score: Athletic Bilbao 1-1 Arsenal
