The Gunners put out a picture on social media of Pepe alongside goalkeeper Bernd Leno, with the caption: "Preppin for the weekend."
The only problem was, they tagged in Ainsley Maitland-Niles rather than the £72million Ivorian.
Pepe spotted the error and commented: "It's me" with a laughing emoji and one with a hand covering a face.
Arsenal quickly deleted the image, although not before it circulated on social media.
Pepe is expected to play some part against Southampton on Saturday despite arriving back late from international duty.