Atletico's Fifa ban on registering players for the next two complete transfer windows means sales are not on the agenda despite Griezmann being linked with a number of Europe's top clubs.
But Simeone, speaking ahead of a home clash with Sevilla on Sunday, has claimed the club will not attempt to keep a player against his will.
He told a news conference on Saturday: "The sporting directors have been speaking to him directly, with those close to him, in order to work out what's best for him and the club.
"Of course he's a very important player for us, but we can't hold him here with chains."
Atletico's rise to the top of La Liga has flown under the radar due to the near-constant focus on Real Madrid and Barcelona.
But Simeone's men have quietly put together another fine season, although their title credentials could be tested by Sevilla, about whom the Argentine was particularly complimentary.
He added: "They're always a very competitive rival. [Unai] Emery has done a great job there, and by always freshening up the squad he's ensured that his side is equally competitive.
"At the moment he's changing things a bit, and is working more on pace in the side with [Kevin] Gameiro and then [Ever] Banega in behind him. This enables them to be a very dangerous team on the counter, because they're moving away a little from the side he started with [Fernando] Llorente and [Vicente] Iborra, with a more tactical set-up and a bigger aerial threat.
"We'll be looking to take the game in the direction we want it to go, which will be attacking with pace and using the channels."