Coach Lee Radford - whose team face his former club Hull FC at the Jungle on Sunday - confirmed: “I think Danny is going to be 11-12 weeks.”
Radford said: “He is in a neck brace at the moment, so it is pretty long term.
“There is a bone fracture in there and it is eight weeks with a brace on then, past that, you’ve got to strengthen everything up in and around there.
“In round one, it wasn’t the news Danny or the club wanted, but it’s the cards we’ve been dealt and we’ll have to be more reliant on Jake Trueman and Gaz O’Brien to grab the team by the horns and get us around the field.”
Loose-forward Adam Milner also remains sidelined after suffering a back injury in pre-season and Radford said he is uncertain when he will be cleared to play.
“We are still struggling with Adam,” he added. “He went to see a specialist [on Tuesday] so it is just a guessing game and a matter of time.
“It’s frustrating because he’d had a really good pre-season and he did it a fortnight before the season started.
“We probably need him right now, to jump in at nine for a period and obviously 13 as well.
“They are all frustrating but, when you see someone have such a good pre-season, it definitely is.”
With Jacques O’Neill also on the long-term casualty list and expected to be unavailable until April, youngster Cain Robb is set to continue as back-up hooker.
Tigers will face Hull without winger Bureta Faraimo and prop Liam Watts who were both suspended by the match review panel this week.
Faraimo received a two-game penalty notice and Watts was banned for one game, both over high tackles in the defeat at Hull KR five days ago.
Neither player appealed against the punishment and Radford said he had no qualms with either charge.
Radford will name an initial 21-man squad tomorrow and confirmed he does have “a few” new injury concerns from last week’s game.