Arsenal agreed to send the 20-year-old out on loan for the upcoming campaign but did not include any obligation to buy.
The plan is still to assess Saliba at the end of the season and look to integrate him into the Arsenal squad.
Technical director Edu said: “Together with William, we have decided it will be good for his continued development to spend another season on loan. William joined us as an 18-year-old, and he is still only 20, so he is still developing all the time.
“William is a player with strong natural ability and next season has the potential to be really beneficial for him at Marseille, a good club. To play another season in Ligue 1 will be very important for his development.
“We will of course be keeping in close contact with William during the season and wish him all the best in France with Marseille.”
Fans have obviously grown furstrated with the treatment of Saliba. The youngster will go into his third season with Arsenal without appearing for a single senior game. The Gunners invested plenty of money in a prodigee like him only to not give him a single chance.
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