Athletic Club return to the UEFA Champions League main stage for the first time in over a decade, and they couldn’t have asked for a tougher opener than hosting Arsenal in Bilbao. For the Basque outfit, who have built a strong reputation in European competition over recent seasons, this is an opportunity to prove they belong among Europe’s most elite competition once again,Softfootball reports.
A fourth-place finish in La Liga last season secured their place, and while their last UCL campaign in 2014/15 ended at the group stage, recent pedigree in the Europa League ,where they reached the semi-finals last season has given their fans hope.

San Mamés has often been a fortress in continental football, with six wins from seven European home games last term , though the only defeat came against English opposition in Manchester United. However, their morale has taken a hit with a 1-0 defeat to Alavés over the weekend, derailing a perfect start to their league season.
Arsenal arrive in Spain with alot of confidence on their side after sweeping Nottingham Forest aside 3-0 in the Premier League. That result reinforced their strength, but it also added a new worry, for the gunners, Martin Ødegaard’s injury. The Norwegian joins a growing list of absentees for Mikel Arteta, creating selection headaches.

Yet the Gunners’ Champions League form remains something they can rely on, only Real Madrid have collected more points in the group stages across the last two editions, and Arsenal have won four of their last five UCL away games, even if they did concede in all of them. Their strong record against Spanish sides having won the last five meetings against any spanish opposition, also to adds their belief heading into this clash.
Team News
Athletic will be sweating on the availability of Nico Williams, who missed the weekend loss to Alavés. Should he fail to recover, the onus will be on Iñaki Williams, who could become the first-ever non-Spanish player to feature for Athletic in the Champions League. He has a habit of striking early, opening the scoring in three of his last four European scoring appearances.
Meanwhile Athletic Bilbao took to the team’s official X handle, to post an emotional video of the long and dramatic reunion of Aymeric Laporte who joined the club in a post-deadline day deal from Al Nassr, and also looking forward with the fans to whats going to be a special tuesday night at the San Mames, as the UEFA Champions League football makes its long awaited return there, watch below;
🎥 INSIDE I A bittersweet evening in a derby in which @Laporte stepped on to the San Mames pitch to greet the fans after full-time.
— Athletic Club (@Athletic_en) September 14, 2025
🇪🇺 It's time to recover and focus on the @ChampionsLeague.
🧣 See you on Tuesday at The Cathedral!#AthleticAlavés #AthleticClub 🦁 pic.twitter.com/Iyr2cmWttJ
For Arsenal, Martin Ødegaard’s injury compounds absences of Bukayo Saka, William Saliba, and Kai Havertz, all of whom were unavailable at the weekend. Summer signing Martín Zubimendi, who scored twice against Forest, will be tasked with carrying that form into Europe, though he personally has a poor record at San Mamés, losing each of his last four visits.
Possible Starting Lineups
Athletic Bilbao possible starting lineup:
Simon; Areso, Vivian, Paredes, Berchiche; Vesga, Jauregizar; I. Williams, Sancet, Berenguer; Sannadi
Arsenal possible starting lineup:
Raya; White, Mosquera, Hincapie, Lewis-Skelly; Merino, Zubimendi, Rice; Madueke, Gyokeres, Martinelli
Additionally, Arsenal via the team’s official X handle, updated the Gunners lovers and supporters from all around the world with latest training pictures and videos of the team’s preparation ahead of the UEFA Champions League season opener against Athletico Bilbao, see below;
UCL mode 🔛
— Arsenal (@Arsenal) September 15, 2025
Check out the training gallery from Sobha Realty Training Centre 👇
SoftFootball’s Prediction
Athletic will rely on their massive home support and defensive compactness to frustrate Arsenal, but the visitors’ depth and experience in European competitions may prove decisive. Expect the Gunners to edge a tight contest.
Prediction: Athletic Club 1-2 Arsenal