Leeds Rhinos will be without England forward Jamie Jones-Buchanan for up to three months with a torn bicep.
Jones-Buchanan suffered the injury in his side's defeat to St Helens on Friday, but stayed on for the duration of the first half.
His bravery has not been rewarded, though, and he is now set for a second fitness-related absence after recently struggling with an Achilles problem.
"It is tough for Jamie as he has only recently come back from an Achilles injury," said coach Brian McDermott of the 32-year-old.
"However, it is a mark of the man that he battled through on Friday to help his team despite the pain he was in. I am sure he will tackle this setback with the same zeal he approaches everything in life and will come back even stronger."