The 18-year-old, who is on loan with Saint-Etienne until the end of the season, has returned to North London to continue his recovery from a groin injury.
Saliba made an appearance at the training ground last week for the first time since completing his £27million summer switch.
And he made the trip to Vicarage Road on Sunday to watch his side draw 2-2 with the Hornets.
My man Saliba in the away end today— Charlie (@afccharlie) September 15, 2019
Come on you gunners pic.twitter.com/y37XJHVYmg