Wigan have failed in their appeal against Maynor Figueroa's red card in the 3-0 defeat at Newcastle.
The Latics defender was dismissed for a challenge on Papiss Cisse just 12 minutes into the match at St James' Park.
Wigan boss Roberto Martinez was unhappy with the decision, insisting the Honduran's challenge was 'shoulder to shoulder' but the appeals panel have backed referee Mike Jones' decision.
Figueroa will now miss Saturday's home clash with relegation rivals QPR.
"We are disappointed, clearly, because we felt we put forward an excellent case," said Martinez.
"We will draw a line under the incident, and continue our preparations for Saturday."
Meanwhile, Adrian Lopez has called on his Wigan team-mates to show mental toughness and pick up a crucial three points against QPR.
Spanish defender Lopez believes the controversial manner of the defeat to Newcastle has unified the squad ahead of the visit of the Premier League's bottom club.
"It was very difficult playing against Newcastle with ten men but, that is behind us now," Lopez told the club's website.
"When a result happens that is out of our hands then what we really want to do is focus on the next game against QPR.
"The whole team has a great relationship, so getting back to our usual positive selves will be easy to do."