Iain Henderson ruled out of Ulster's Pro12 game with Munster
Iain Henderson has been ruled out of Ulster's Pro12 game against Munster on Friday with a shoulder injury.
The second row sustained the injury during the Irish province's Champions Cup win over Exeter at the weekend.
Henderson is also a major doubt for Ireland's autumn Test series as he is set to be out for two to four weeks.
Darren Cave and Robbie Diack are available again for Ulster after overcoming injuries but Luke Marshall, Stuart Olding and Dan Tuohy are doubts.
Marshall's knee problem and Tuohy's hip complaint have been described as 'low grade' by Ulster and their progress will be monitored throughout the week.
Ulster medical staff are optimistic the pair will be fit but both teams could be without a raft of Ireland internationals ahead of the autumn internationals, including Ulster's Jared Payne and Rory Best.
The Ireland squad will fly to Chicago early next week ahead of their Test against New Zealand at Soldier Field on Saturday 5 November.
Olding suffered a hip flexor injury in Saturday's Pool 5 victory at Kingspan Stadium, in which locks Peter Browne and Alan O'Connor, and props Rodney Ah You and Ross Kane were also injured.
All four forwards will miss Ulster's second interprovincial clash of the season in Belfast on Friday, with former Connacht front-rower Ah You likely to be out of action for four to five weeks.
Another lock, Kieran Treadwell, is doubtful with an ankle injury.
Chris Henry, Marcell Coetzee, Louis Ludik and Stuart McCloskey are among those who remain on the long-term absentee list.
Pro12 leaders Ulster, who lost to Connacht in their last domestic outing, lie three points ahead of fifth-placed Munster in the standings.
Munster beat Glasgow 38-17 in the Champions Cup at Thomond Park on Saturday in their first match since the sudden death of their head coach Anthony Foley.