Hull FC centre Jordan Turner will join St Helens at the end of the season after signing a two-year contract.
The 23-year-old will link up with team-mate Willie Manu, who has also agreed a move to Langtree Park.
Former Salford man Turner, who can also play in the back row, has scored six Super League tries this season.
"Jordan is one of the most exciting talents in the game and we are delighted to secure his services," said Saints chairman Eamonn McManus.
He told the club website: "Not only does he possess good feet and a great turn of pace, but he's matured into an excellent defender too.
"At 23, he is still developing and will no doubt do so further under Nathan Brown and his staff."