Addy is a versatile Scotland international able to play across a number of positions but predominantly loose forward or stand-off.
A key member of the Bradford side for a number of years, the 25-year old has racked up over 150 first team appearances and is also an accomplished goal-kicker.
Born in Pontefract but raised in New Zealand, 23-year old Clark is a former Junior Kiwis international who followed in his father’s footsteps by playing for the Bulls.
The duo boast impressive records in the Kingstone Press Championship and have penned one-year deals with the Robins with further options for 2018 and 2019 subject to the club’s league status.
“We’ve been looking to increase the depth of the squad and both players have plenty to offer.
“Although they are still in their early to mid-20s, they have plenty of experience for their age, have a good knowledge of the Championship and they are both hungry to come to Hull KR and make an impression.
“Danny is able to cover a number of positions to a high standard whilst Mitch is a big prop with bags of potential. He’s got time on his side until he hits his peak as a front-rower, but he’s a strong ball carrier who will provide the team with some real impact and go forward.
“Although we had initially agreed contracts with them earlier this season, both Danny and Mitch have shown they are up for the fight next year and are committed to helping us push for promotion back up to Super League in 2017.”