The Frenchman has been linked with Barcelona.
Gil Marin admits the arrival of Diego Costa has changed the situation.
"I know Diego [Costa] well and I know that Atletico is his place in the world," Gil Marin said to 'Mega' at the LaLiga Promises International Tournament.
"It's been a blessing for both of us that we have him for two more seasons.
"As we continue to grow this relationship of complete symbiosis, the two sides win."
On keeping Griezmann, Gil Marin was more guarded.
"I can't tell you what will happen because it doesn't depend on us," he continued.
"Last summer we made an effort far beyond the real possibilities of Atletico for him to stay.
"We will do the same thing again next summer because it took us a lot to get these two players together."