Alexandre Lacazette was picked to start ahead of Aubameyang, who has scored six goals in his last seven games.
“He (Aubameyang) was going to start the game, we had a disciplinary issue. We have drawn the line and we move on. He’s on the bench,” said Arteta.
Asked if he would explain what Aubameyang had done, Arteta said: “No. Obviously we keep that internally. We have a process that we have to respect for every game and that’s it.”
Sky then pressed Arteta to say if he had debated leaving Aubameyang out of the squad, he said: “It is a decision made after evaluating everything, and who Auba is and what’s he done and that’s it.”
Former Arsenal player and interim manager Freddie Ljungberg said of Aubameyang: “The only thing I can think about is maybe he has been late or something, because [if] you still keep him on the bench it can’t be that bad.”
Arsenal XI: Leno, Cedric, Luiz, Gabriel, Tierney, Thomas, Smith-Rowe, Saka, Odegaard, Xhaka, Lacazette
Subs: Bellerin, Ceballos, Willian, Aubameyang, Holding, Pepe, Chambers, Elneny, Ryan