Ulster expect to have captain Johann Muller back on duty for their final RaboDirect PRO12 league-phase game.
Following tests to determine the extent of the bicep injury he suffered to his left arm after 64 minutes of Saturday’s Heineken Cup quarter-final defeat by Saracens, Ulster confirmed that the South African lock forward will be out for three weeks.
That means he misses Friday night’s home date with NG Dragons and the trip to Galway for the inter-pro clash with Connacht a week later.
But he is expected to return to lead Ulster against Cardiff Blues on May 3, a potentially crucial fixture in terms of securing a home semi-final in the PRO12 play-offs.
Centre Luke Marshall, who was examined by a specialist yesterday after suffering concussion in a third successive match, will be seen by another expert in the field later this week.
Until that second examination has been carried out, Ulster cannot say how long they are likely to be without their 22-year-old Irish international midfielder. The fear is that he will be out for the remainder of the season, which would create a major problem in view of the injury crisis to have jinxed the number 12 channel.
Chris Farrell has been missing since September after suffering an anterior cruciate ligament tear and Ireland international Paddy Wallace ruptured his ACL in Ulster’s February 22 defeat by Glasgow Warriors at Scotstoun.
Stuart Olding is the obvious replacement for Marshall, but there is no cover after that. Jared Payne, Andrew Trimble or fit-again Tommy Bowe could, in a crisis, move out of the back three, however.
l Jonathan Sexton could be in line to make his return from a foot injury when Leinster meet Munster in the RaboDirect PRO12 on Saturday.
The Ireland fly-half has not played since suffering a hamstring injury in the Six Nations defeat against England, with a tendon tear in his left foot further extending his spell on the sidelines.
But Leinster say Sexton has “stepped up his rehabilitation in recent days”, and could be involved at Thomond Park.
The 27-year-old is among the favourites to wear the Lions' number 10 jersey in Australia, and head coach Warren Gatland will welcome the news Sexton is closing on a return to fitness.
Brian O'Driscoll will make his return to action for the province in Limerick, with his ban for stamping during Ireland's defeat in Italy set to expire.