"I think Sunday, it's the final match of my career," 70-year-old Gasset said ahead of this weekend's game at Le Havre.
"That I stay in football, use my experience, my ideas, my connections, is possible. And then I don't know how to garden, so I won't have anything to do. But as a coach, it's over."
Gasset joined Marseille in February, replacing Gennaro Gattuso after being sacked as Ivory Coast coach midway through the Africa Cup of Nations.
He was dismissed by the tournament hosts after an embarrassing 4-0 defeat by Equatorial Guinea in the group stage.
The Ivorians scraped through to the knockout phase as the last of the four best third-placed teams to advance, remarkably going on to win the tournament for a third time.
"I wanted to finish in style. It's an honour for me to have coached Marseille," added Gasset, who was formerly assistant coach to Laurent Blanc with France and Paris Saint-Germain.
"There were times at the Velodrome where I had goosebumps. Coaching Marseille is very demanding work."
Marseille reached the Europa League semi-finals but are eighth in Ligue 1 and no longer have European qualification in their own hands.
