Ben Evans has been ruled out for up to four months having undergone surgery to resolve an ongoing hip problem.
Evans, 20, is on a season-long loan from Warrington to Bradford, but the Wales forward is set for a lengthy spell recovering and will be on crutches for around six weeks.
He said: “It’s disappointing but it’s been nagging for a while and it will be good to get it sorted so I can start playing rugby again.
“I was looking forward to playing Super League rugby regularly but unfortunately I will be out of action until March/April time.
“It could have been worse though and at least once it’s sorted I will have the rest of the season to look forward to.”
Bulls coach Francis Cummins intends to stand by his signing until he is able to feature again, but hasn’t ruled out making further additions before the season starts.
“Ben has been with us for two months and you don’t just turn your back on someone. It’s unfortunate what has happened but it’s about getting his body right for when he is fully recovered.
“It’s disappointing for Ben and for the club because we had high hopes for him this season.”