Both will undergo surgery to arm injuries the pair have picked up this season.
Coach Peter Gentle admits selecting a fully fit side to face Leeds on Friday may prove tricky.
He said: “It’s obviously a huge blow to lose two more of your first-team squad for such a long period of time, particularly players like Sam and Danny who are a key part of our team.”
“It definitely leaves us a little short, we’re not having the best run of luck with injuries at the moment but that is part of the game and we must roll our sleeves up and get on with it.
“We have a team who are very confident regardless of what side we put out and who we play against and they know they’ll need to continue to dig deep for the rest of the season and work very hard.”
Assistant coach Lee Radford may make another re-appearance as a direct result of the Airlie Birds’ injury crisis.
Radford last stepped out of retirement to help the Black and Whites defeat Hull KR earlier this season. He may be considered for selection again on Friday, which would be a blow to National Conference League side East Hull, who Radford had been playing for in an amateur capacity.
Gentle said: “Lee has been chomping at the bit ever since he last played for us, that is the sort of character he is and he still leaves his boots in the coaching office all cleaned up just in case.
“He is the perfect person to have around the place at a time like this, he keeps himself fit and strong and his enthusiasm and commitment when he plays makes up for any short falls in training or match fitness.
“It could be one option for us and should we go that way again I am under no illusions that he can go into our team and do a job for us, just like he did earlier this season.”
Radford scored a try in that 36-6 defeat of Hull KR upon his return.