Hull have signed teenage brothers Tom and Jack Briscoe from Featherstone Juniors amateur club.
Jack has penned a two-year deal and Tom has agreed a three-year contract.
Tom, 17, who has scored five tries in the club's three pre-season trial games, is a centre or winger while Jack, 16, is a full-back or winger.
Coach Peter Sharp said: "These boys are two of the most exciting prospects in the game. I can see both having big futures."