Simeone says Atletico are closer to rivals Real following the sale of Cristiano Ronaldo and is flabbergasted as to why Griezmann failed to make the top-three shortlist for The Best FIFA awards.
Madrid won the Champions League for a third consecutive season with Ronaldo once again the driving force in that triumph with 15 goals in the tournament.
But the Portugal captain left LaLiga in a sensational €112m switch to Juventus in July following nine trophy and goal-laden seasons at the Santiago Bernabeu.
And Simeone believes his team, who finished above Madrid in LaLiga last term and defeated Los Blancos in August's UEFA Super Cup, are now on a more level playing field with their city rivals.
"From the results, we aren't worse than Madrid or Barca, from the individual characteristics of our players, yes," he told El Partidazo de COPE.
"Without Cristiano, we have approached Real Madrid level, for sure."
Simeone was also quizzed on Griezmann, who over the past four months has become a World Cup winner with France and helped Atleti to Europa League and Super Cup glory.
However, Griezmann did not make the shortlist for the Best FIFA Men's Player, with Ronaldo, Luka Modric and Mohamed Salah battling it out - a decision the player himself labelled 'bizarre'.
"He hasn't had an explanation - World Cup winner, Super Cup, Europa League, second in LaLiga, best player in the [World Cup] final," he added.
"In this past year, he was the best in the world. It is a pity. We do not underestimate ourselves to think that it is because he plays for Atletico, it will be a lack of imagination of people who choose.
"Obviously it disappoints a little. But it's clear that Griezmann was the best last season."