It was the third time the France defender played away from the club since he was signed from Saint-Etienne in 2019.
The 21-year-old played a key role as Marseille finished second in Ligue 1.
He subsequently expressed his desire to stay at Stade Velodrome to play Champions League football.
However, Saliba has now performed a U-turn on his future.
“I belong to Arsenal, and I still have two years there. I will be there for pre-season with Arsenal.
“I have played zero matches with Arsenal and I want to show them what I’m made of and have the chance to play for the supporters and for this big club.
“That depends only on me. In any case, leaving (Arsenal) like that would be a shame,” Saliba has told Telefoot.