Ulster will be without Charles Piutau, Sean Reidy and Rob Lyttle for several weeks after the trio suffered injuries during the win over Southern Kings.
Ulster say Piutau will be unavailable for a number of weeks after the full-back dislocated a rib cartilage.
Reidy will be sidelined for up to six weeks with a knee ligament injury while Lyttle is facing four to six weeks out with a hamstring strain.
Ulster host Conference B rivals Edinburgh on Friday, 16 February.
Piutau appeared to be in some distress as he was replaced during the opening quarter of the win against the Kings and the former All Black is now likely to also miss the upcoming match against Scarlets.
Piutau, 26, has already confirmed he will leave Ulster at the end of the season to join English club Bristol.
Lyttle appeared to damage his hamstring in the act of scoring his second try during the 59-10 defeat of the South African side.
Ulster also confirmed that Reidy sustained a medial knee ligament knee during the first half of the match, which was Jono Gibbes’ first game as head coach.
In a statement, Ulster also revealed that Andrew Trimble (back) and Peter Nelson (hamstring) have returned to training and are in contention for Friday’s visit of Edinburgh.
Wing Tommy Bowe is likely to be available for selection.
However, the province are still without Marcell Coetzee and Jared Payne, who are recovering from long-term injuries.