Jonathan Walker has left Castleford to play his club rugby alongside twin brother Adam at Hull Kingston Rovers after agreeing a three-year contract.
Adam joined the Robins a year ago from Huddersfield and Jonathan become the Super League club's fifth recruit for 2014 after cutting short his four-year stay at the Tigers.
The 22-year-old prop forwards were together at Bradford's academy before going their separate ways but have played together for Scotland and will be reunited for the World Cup.
Jonathan, who joins Michael Weyman, Neville Costigan and Jamie Langley as part of a new-look Hull KR pack in 2014, says he spoke to his brother, as well as Castleford's former Rovers centre Jake Webster, before opting to make the move.
"I first heard of Hull KR's interest a couple of months ago and spoke to my brother and Jake Webster about the club," he said.
"They both had nothing but good things to say about the place and every time I spoke with Adam last season, all he talked about was how much he enjoys it at Hull KR.
"I've watched him progress, play plenty of minutes and really enjoy his rugby and it's something which I aspire to as well.
"As brothers, we are competitive and I think playing together will help to drive us on even more and improve our games. Playing for the same club is something we've always wanted to do, so to get this opportunity is great and one that I'm really looking forward to."
Rovers announced the signing of Jonathan days after Adam agreed to extend his contract to the end of 2017.
Hull KR chief executive Mike Smith said: "Jonathan is a young, British player with his best years in front of him. Not only is he a talent on the pitch, he also has the type of character that we're looking for here at Hull Kingston Rovers.
"We've always said that when you sign a player you need to be sure that they fit into the culture of the club and the squad, and Jonathan fits that bill. He's excited about joining us and I'm sure our supporters are looking forward to seeing him link up with Adam, who was one of our stand-out players last season.
"Jonathan is the latest piece in the jigsaw that we're creating for 2014 and we believe we'll have a squad which will be very competitive."
