Prop Adam Macklin damaged his knee playing for Ulster Ravens against Bristol over the weekend. He will be subject to an ongoing conservative management programme and will be reviewed in due course.
Out-half Paddy Jackson was assessed yesterday for an ankle injury he picked up against Glasgow, as was winger Craig Gilroy who suffered a bang to the head during the round 5 fixture.
Jackson's ankle is responding well to physiotherapy treatment, while Gilroy is following the necessary return-to-play protocol.
Ulster are hopeful that both players will be available for selection for next weekend's Heineken Cup round 6 trip to Castres Olympique.