Tavares was presented to the local press on Friday.
He said, "My agents and I have always wanted a purchase option. Arsenal have never expressed themselves in this sense. They didn't want there to be one. But we, of course, wanted there to be one but it was not possible.
"Now it is no longer important. I am in Marseilles. With or without a purchase option, I'm happy."
Tavares continued: "Is my arrival linked to competition? I do not know. For me, that's not the point. I came to Marseille to be allowed to play my position. I can evolve in my position whether in the Champions League, in the league or in the Cup. I came to play my position. Marseille gave me this opportunity, whereas at Arsenal I would probably only have played in the Cup if they made me stay.
"So I decided that it was better for me to go to a team where I was given the opportunity to be able to fight to play my position."