Manchester United, Manchester City, Liverpool, Arsenal, Chelsea, Tottenham, Real Madrid, Barcelona, Juventus, Milan and Inter are said to be the other sides involved, though the proposal reportedly includes an expansion option to 16 or 18 teams.
UEFA responded strongly, insisting it will do everything in its power to block the plans, including banning the 12 clubs from their own competitions, while there has also been a suggestion that players involved may not be allowed to represent their countries on the international stage.
Speaking after his side's 5-0 thumping of rock-bottom Eibar on Sunday, Simeone said he had no doubts any decision made by Atleti would have the club's best interests at heart.
"We are prepared to train the clubs," he told a media conference. "Our club will make the best decision for our future.
"I am a coach and I am prepared to train wherever they tell me. I have no doubt that the club will decide what is best for us."
Atleti tightened their grip at the LaLiga summit with a clinical win over Eibar, who did not register a single shot.
Angel Correa put Atleti 2-0 up at the interval – his first brace in 273 games across all competitions for the club – before Yannick Carrasco added a third shortly after the interval.
Marcos Llorente then added a double of his own to wrap up all three points in style, the Spaniard's first helping him reach 10 LaLiga goals in a season for the first time in his career.
It marked just Atleti's fifth win in their past 12 LaLiga matches, but they still have a slender advantage over neighbors Real Madrid and Barcelona as they bid to win a first title since the 2013-14 season.
Atleti did not have a shot on goal until the 34th minute and Simeone was pleased with his side's renewed dynamism after the interval.
"Goals always generate enthusiasm and energy," he added. "The second half was not the same as the first; we were much more dynamic, precise, with more movements. Energy and winning always gives you strength.
"The most important thing is to be able to win. It is what gives you peace of mind for the next day."
Correa has now been involved in 17 goals this season across all competitions (six goals, 11 assists) – just one behind his best ever return for Atleti in a single season (18 in 2016-17 and 2017-18).
Simeone was pleased with the Argentina international's contribution after a season which has seen him feature in every LaLiga game.
"We have been working together for many years," Simeone said. "We understand when to talk and when to leave the footballer alone and the numbers speak for themselves in the confidence we have in him; he is the only one who has participated in all the games of the season."