Leeds have failed in their appeal against Jason Pearce's sending-off in the 6-1 defeat by Watford on Saturday.
Pearce was shown a red card by referee Trevor Kettle for a challenge on Matej Vydra, and that punishment has been upheld meaning Pearce will have to sit out three games.
His ban starts with Sunday's trip to Millwall, which midfielder Michael Brown will also miss after reaching five yellow cards this season.
Reacting after his dismissal Pearce said: "I was massively disappointed. I'm a wholehearted player. I genuinely went for the ball.
"Looking back I thought it was a yellow card. I went for the ball, and I kicked him but it wasn't a bad tackle or a dangerous tackle so I'm disappointed."