Ulster's injury woes have deepened after Paddy Wallace was ruled out for the remainder of the season with a knee injury.
The 33-year-old ruptured the anterior cruciate ligament in his left knee during Ulster's PRO12 defeat at Glasgow last Friday, with scans showing he requires surgery.
Wallace, who filled in at fly-half at Scotstoun in the absence of Ireland international Paddy Jackson, was clearly struggling early in the second half and was replaced shortly after Peter Murchie blocked down his clearing kick to score the hosts' third try.
Ulster said in a statement that Wallace "will require surgery and a significant period of rehabilitation".
The loss of Wallace means Ulster will be without three of their key players for their Heineken Cup quarter-final against Saracens at Twickenham on 6 April.
Wing Tommy Bowe is continuing his rehabilitation from a knee ligament injury but the Saracens game will come too soon, while fellow Ireland international Stephen Ferris could miss the rest of the season after suffering a setback with his ankle injury.