Connacht prop Denis Buckley has been ruled out for the remainder of the season after he underwent surgery on an ankle injury this week.
Buckley has been sidelined since the end of April after fracturing his ankle in training.
It is expected that he will return to full training at the start of the pre-season in late June.
Meanwhile, Buckley's team-mates Rodney Ah You and Finlay Bealham have completed the graduated return-to-play protocols for their head injuries.
Both props joined full training this week and are available for selection for Saturday's semi-final against Glasgow Warriors at the Sportsground.
Ronan Loughney has recovered from the shoulder injury sustained in the last game against Glasgow and is also available for selection this week.
Craig Ronaldson is also available for selection having recovered from the ankle injury sustained earlier in the season.
Danie Poolman has resumed training this week with the main squad following his foot injury but remains unavailable for selection, while tighthead prop Nathan White has resumed fitness training and will be progressed over the coming weeks.