Connacht prop Ronan Loughney is expected to be out for about two or three weeks with an ankle injury.
The 29-year-old Galway man will undergo a scan tomorrow after picking up the injury during the Challenge Cup defeat to Exeter.
There was better news for Matt Healy and Dave McSharry though, who have returned from minor knocks and will be available for the Pro12 game against Ospreys at Liberty Stadium this Friday night.
Elsewhere, lock Aly Muldowney is suffering delayed onset concussion symptoms and will be required to undergo the standard return-to-play protocols this week.
Meanwhile, Ireland squad members Robbie Henshaw, Kieran Marmion, Darragh Leader, Nathan White and Rodney Ah You will join up with the Ireland squad at Carton House on Tuesday as preparations pick up for the 2014 Guinness November Series.
The Connacht team to face Ospreys will be named on Thursday at noon.