The Blaugrana looked closer to their best against the Basque side, with Lionel Messi and Pedri in particular displaying a lovely cohesion - something that has been desperately lacking at times in the Barca forward line this campaign.
Messi scored two goals on the night, while Pedri recorded a goal and an assist.
Also part of that forward line was Antoine Griezmann, who recorded an assist for Messi for the third goal which proved to be the match winner.
Martin Braithwaite started the previous game - a 1-0 win against Huesca - but Barcelona simply looked much, much better with Griezmann included versus Athletic so expect the Frenchman to retain his place.
Barca played in a 4-3-3 in that one, with Griezmann on the left and Messi through the middle.
Ousmane Dembele will likely start again, too.
In fact, it is unlikely Koeman will make any significant alterations to the front six which started against Athletic, with Sergio Busquets and Frenkie de Jong starting in the middle of midfield alongside Pedri.
The Dutchman will, however, be forced into one change in defence as Clement Lenglet is suspended after an accumulation of yellow cards.
Koeman seems to trust Oscar Mingueza more than Samuel Umtiti, so expect a back four of Sergindo Dest, Mingueza, Ronald Araujo, and Jordi Alba.
Marc-Andre ter Stegen will start in goal.
In terms of injuries, Barcelona are still missing Ansu Fati, Sergi Roberto, and Philippe Coutinho, with the Brazilian set to miss three months of action.