X-rays to Utai’s left forearm revealed an underlining fracture, requiring the former Canterbury player to remain in a cast for up to a month.
He is expected to return in round 18.
As well as Utai, coach Tim Sheens will also be without fullback Wade McKinnon for Monday’s clash with Newcastle after he injured a hamstring prior to the 24-18 loss to the Dragons.
“It wasn’t one of those ones where we could afford to send him out there and lose him 50 minutes into a game for the next six weeks,” Sheens said.
“He has had trouble with it. It was just a twinge. It might cost him a week next week but it wasn’t worth at that point risking a five or six week injury with his history of hamstrings.
“With Lote having a broken arm, you don’t want to see it broken again so we have to be 100 per cent sure there.”