Dan Tuohy is out of Ulster’s Heineken Cup clash against Glasgow at Ravenhill tomorrow night.
The Ireland lock is also likely to miss the final Pool 4 game away to Castres the following week due to a troublesome calf injury which flared up again during last week’s bonus-point win over the Scarlets.
Coach Mark Anscombe is set to bring in Ireland blindside Iain Henderson to partner Lewis Stevenson in the second row, while Robbie Diack looks set to continue in the No 6 jersey in the back row alongside skipper Chris Henry and Nick Williams.
Ulster have nominated Dungannon winger Chris Cochrane as an additional player with his injured club colleague Chris Farrell deregistered.
The 24-year-old has made six appearances for Ulster and is likely to find himself on the bench for Friday night’s clash. With full-back Adam D’Arcy fracturing his ankle last Friday, Kiwi Jared Payne is now almost certain to start.