Harlequins flanker Chris Robshaw and fly-half Nick Evans have been ruled out of the European Champions Cup match against Leinster in Dublin.
England captain Robshaw, 28, is struggling with a shoulder injury and has been referred to a specialist.
Fly-half Evans, 34, has groin and back problems and went off after 11 minutes of
He is, however, expected to return for the home Premiership game against Newcastle Falcons on 20 December.
Harlequins say they will provide an update on the pair's condition in the coming days.