William Saliba was left out of the squad that took on Fulham because Mikel Arteta is keen to ease the defender into the first-team set-up.
The 19-year-old linked up with the Arsenal senior team for the first time this summer having spent last season on loan at St Etienne.
Summer signings Willian and Gabriel were included and were handed their debuts by Arteta, but there was no room for Saliba on the bench.
After the team news was revealed, Goal reported Saliba was not injured and instead was just being eased into the team.
Saliba has only ever played in France, but is considered a massive talent by the Arsenal hierarchy who forked £27million to sign the centre-back last year.
Gabriel, 22, beat Saliba to the starting place against Fulham and Arteta confirmed he felt the Brazilian had to play.