Ibrahima Sonko has failed in his attempts to overturn the suspension and fine handed out to him by Reading.
The defender was punished for refusing to play for the club's reserve side, but launched an appeal on Wednesday to get the decision revoked.
However, Royals' director of football Nick Hammond has upheld manager Steve Coppell's decision to discipline the Senegalese centre-half.
Emerse Fae, who was handed the same penalty as Sonko, decided not to appeal, but has made it clear that he wants to leave the Madejski Stadium over the summer.
"Sonks did appeal," Hammond told the Evening Post.
"I think he wanted to clear things up and bring things to a conclusion, which is what we did."