The England Knights international, 24, missed Sunday’s opening game of the season, the win against Huddersfield Giants.
Head coach Brett Hodgson today revealed he has needed surgery that will sideline him for at least eight weeks.
Hodgson said: “Masi went in on Saturday for an operation to get his meniscus repaired.
“We need to see the extent of how that goes over the next fortnight to determine how long that break for him will be.
“At this stage, it’s going to be a substantial period of time. We’re thinking at least a couple of months
“I really feel for the kid. I know he’s had some bad luck with injury over the last couple of years and he was and still is a big part of our plans going forward.
at this stage.”
Hull are also without fellow front-row Josh Bowden for Saturday's game against Salford Red Devils after he departed the Huddersfield Giants win with concussion.
Support The Yorkshire Post and become a subscriber today. Your subscription will help us to continue to bring quality news to the people of Yorkshire. In return, you'll see fewer ads on site, get free access to our app and receive exclusive members-only offers. Click HERE to subscribe