Atletico face Marseille in the final of the European sister competition on Wednesday night, but they will have to do it without Simeone in the technical area.
The Argentine was handed a ban after confronting the referee during Atletico's semi-final first leg against Arsenal, an action that saw him sent to the stands.
However, the La Liga outfit had asked the Court of Arbitration of Sport for a precautionary acceptance to allow Simeone to sit on the bench for the final in Lyon.
Despite their best efforts, CAS decided against their request and the ban will be upheld in what could be a massive blow to 'Los Rojiblancos' chances of success.