Pepe scored during Tuesday’s 2-1 defeat to Wolves and he has now struck in his last three League games away from home.
The Ivorian’s place is now under threat given Aubameyang is back, but Arteta says every player must earn his spot – even the Arsenal captain.
“At the end of the day, we have to play the players who are in the best form and everybody has to earn the right to play and participate in the games,” he said.
“That’s what everybody’s doing, pushing each other to raise the level. You can see that the level has been raised because everybody is playing at their best.
“There’s still room for improvement so everybody has to keep pushing.”
Arsenal are due to be without Bernd Leno and David Luiz for Saturday’s trip to Aston Villa as both were sent off during the defat to Wolves – and the Gunners’ appeal against Luiz’s dismissal was rejected by the FA on Thursday.
Leno’s absence means either Alex Runarsson or Mat Ryan will start in goal, but the latter has a hip issue.
Arsenal are hoping Ryan will train in the coming days, but if not Runarsson is due to play.
Arsenal predicted lineup: Runarsson; Bellerin, Holding, Gabriel, Cedric; Partey, Xhaka; Saka, Smith Rowe, Pepe; Lacazette.
Tuesday 12.30pm GMT, BT Sport
Arsenal squad from: Runarsson, Ryan; Bellerin, Cedric, Chambers, Gabriel, Holding, Mari, Tierney; Ceballos, Elneny, Odegaard, Partey, Saka, Smith Rowe, Xhaka; Aubameyang, Balogun, Lacazette, Martinelli, Nelson, Nketiah, Pepe and Willian.
Doubts: Ryan (hip), Tierney (lower leg).