Centre-half Jim Lauchlan, one of the heroes of United's draw with Rangers on Sunday night, will have to sit out the next two games.
Lauchlan, who has been in outstanding form since his move from Kilmarnock, will serve a two-match suspension taking in Saturday's visit to Hearts and the Boxing Day clash with Celtic. "It is a blow to be losing Jim right now because he was superb against Rangers and has been doing very well, but we do have options when it comes to finding cover for him," said Manager Alex Smith on Monday.
Also missing on Saturday will be Argentine striker Beto Naveda, stretchered off with a knee problem against Rangers. His condition, however, is not as bad as first feared and a ligament strain should only see him miss the one game.