The France international has been heavily linked with an exit at the end of the season, with Manchester United and FC Barcelona reportedly keen.
Simeone insists he would never stand in the way of one his players' desire to move on.
"I love my players a lot and I love to see them grow. I am not ungrateful," Simeone told L'Equipe.
"If a player comes to me and says, 'Coach, I have a once in a lifetime chance to play for a certain team, I want to leave'. If he did all he could for me as Griezmann does, I'll say it's no problem. I know that he needs to grow.
"Of course Griezmann will be able to leave at some point, the same way Costa and Arda Turan were allowed to leave."