The back rower sustained the injury in the recent game against Widnes, and he will be out for around a month.
“Yes, Mass is injured,” he said.
“He picked up an ankle syndesmosis injury against Widnes and will miss three or four weeks.
“But we are going ok at the moment, we’re in a bit of a groove, so the squad (for this weekend) will be pretty similar otherwise.
“It’s not great, but it certainly isn’t as bad as it could have been. Mass will be fine for the Super Eights which begin in earnest in just a few weeks’ time, so that will be great.
“He has been going really well for us.
“It is disappointing for him of course, getting another injury, but that’s life and he’ll be alright. There’ll still be plenty of the season left when he comes back.”