Ulster number eight Nick Williams has played his last game for the province after failing to recover from a shoulder injury.
Williams is leaving Belfast after several successful seasons to join PRO12 rivals Cardiff Blues.
The 32-year-old has been unsuccessful in his bid to rehabilitate his recent shoulder injury and will undergo surgery this week to repair a labral tear. This will rule him out for the remainder of the season.
In other news, Wiehahn Herbst has begun to reintegrate into team training sessions and the medical team is confident that he will be available for selection within the next two weeks.
Tommy Bowe experienced a mild knee reaction following the recent game against Zebre and he will be unavailable for selection this week.
Both Louis Ludik and Paul Rowley remain unavailable for selection as they continue to rehab their respective groin and knee injuries.
Ian Humphreys has seen a spinal specialist and had a recent injection for his ongoing back injury. He continues to rehab for this injury.
Alan O'Connor had surgery ten days ago following his recent shoulder dislocation. He is expected to be fit for the beginning of next season.
Sammy Arnold is continuing to rehab his hamstring injury but he is unlikely to be available for the remainder of the campaign.
Dan Tuohy (ankle), Peter Nelson and Willie Faloon (both midfoot) continue to rehab their respective season-ending injuries.