Saliba spent last season on-loan with OM and has been outstanding for the Gunners so far this term.
Italian transfer expert Fabrizio Romano declared last night: "Olympique de Marseille had a direct meeting with Saliba's agent in August, but it was then impossible to negotiate the price with Arsenal.
"They considered William untouchable. There was not even a direct discussion."
Saliba's deal with Arsenal expires in 2024.