Celtic have had a busy summer in terms of matches, playing six friendlies in total, including a 1-1 draw with Premier League outfit Wolverhampton Wanderers on Saturday.
The Hoops will open their 2023-24 Scottish Premiership campaign at home to Ross County next Saturday, meaning that the clash with Athletic will represent their final friendly of the summer.
Brendan Rodgers’s side have been very active this summer in terms of arrivals, with Maik Nawrocki, Odin Thiago Holm and Yang Hyun-jun among those to join the club, while Jota has been their biggest departure, making the move to Al Ittihad in a big-money deal.
Celtic won the Scottish Premiership on 99 points last season, seven clear of runners-up Rangers, and it is set to be another fascinating battle for the title in the coming campaign.
Rodgers’s side will compete in the group stage of this season’s Champions League, meaning that they can focus on making a strong start to their league campaign.
Athletic, meanwhile, have played four friendlies this summer, with their last match taking place on Saturday, suffering a 2-1 defeat to Gimnastic Torrelavega.
The Basque outfit have two more pre-season games after this one against Eibar and Manchester United before beginning their La Liga campaign at home to Real Madrid on August 12.
Athletic have made two signings this summer, bringing in Inigo Ruiz de Galarreta from Mallorca on a free transfer, while Javier Marton has made the move from Real Sociedad.
Inigo Martinez has been the major departure, but the club have managed to keep the likes of Inaki Williams and Nico Williams despite speculation surrounding their futures, and Ernesto Valverde’s side will again be pushing for a European finish in the coming season.
The Lions were eighth in Spain’s top flight last term, two points behind seventh-placed Osasuna, meaning that there will be no European football at the club in 2023-24.