Top scorer Sam Cosgrove will miss Aberdeen's final two matches before the winter break after losing his appeal against a red card shown in the loss to Celtic.
The 23-year-old will serve a two-match ban, ruling him out of games against Livingston and Hearts.
He was shown a straight red card for a tackle on Celtic's Kristoffer Ajer in a 2-1 defeat at Celtic Park.
"It's a brilliant tackle," Aberdeen boss Derek McInnes said afterwards.
"I have watched it 20 times and Cosgrove has won the ball cleanly. He probably doesn't need to go in as quick as he does but he has won the ball cleanly," McInnes added.
But an independent tribunal upheld the decision of match referee Euan Anderson.
Cosgrove, who has scored 20 goals this season, has been sent off three times since joining Aberdeen and two of those have come against Celtic.