Munster forwards RG Snyman and Dave Kilcoyne will undergo MRI scans today to determine the nature of their injuries.
High profile new signing Snyman suffered a knee injury just seven minutes into his debut in Saturday's PRO14 defeat to Leinster and afterwards Reds boss Johann van Graan described it as a "pretty serious" injury.
Kilcoyne came off in the same minute with an ankle injury, and both will be assessed further today - as well Snyman's second row colleague Jean Kleyn, who replaced him at the Aviva Stadium but had to come off with a neck injury.
Kleyn underwent imaging in hospital and was discharged. He will undergo further imaging today to investigate.
Meanwhile, Kilcoyne had only started the game due to a low grade groin strain suffered by fellow tighthead James Cronin last weekend and he will continue to rehab with the medical team.
Flanker Jack O’Donoghue suffered a concussion in training last week and will follow the graded return to play pathway under supervision of the Munster medics.
All four are expected to miss out as Munster chase down two more points in their final regular season game against Connacht at the Lansdowne Road venue on Saturday, but full-back Mike Haley will return to training this week after a calf problem and could be involved.
Joey Carbery (ankle), Dan Goggin (ankle) and Roman Salanoa (abdominal) are continuing to rehab.
