Hull KR have agreed a two-year deal with Jamaica international Omari Caro.
The 21-year-old, the fastest man in rugby league, will make the switch to the Robins from the London Broncos.
Caro, who appeared 12 times for the Broncos this season, said: "I had one or two options but once I'd spoken with Craig (Sandercock) it was a no-brainer for me. He has a reputation for developing younger players and I'm keen to work with him.
"I'm sad to leave London as my whole playing career has been with the Broncos and I've lived down there all my life but this is a great opportunity for me and I didn't want to let it slip by."
Rovers coach Sandercock added: "Omari fits the profile of the type of the player we want to bring into the club.
"At 21 he's still in the early stages of his career and someone that we believe will get better and better.
"Obviously he has real pace but there's a lot more to his game than that and when I met him I was impressed with his eagerness to learn and knowledge of the game."