Castleford Tigers hooker Daryl Clark will join Warrington Wolves at the end of the season on a four-year contract.
The 21-year-old has been one of Castleford's star performers in 2014, helping the Tigers to a first Challenge Cup final in 22 years and fifth position in the Super League table.
His form earned him a call-up to Steve McNamara's England squad in June.
Castleford chief executive Steve Gill confirmed the move had been completed last year to secure the Tigers' future.
|Daryl Clark on leaving Castleford|
|"This is my hometown club and I will always be a Cas fan. My proudest moment has been helping this team reach the Challenge Cup final and I'll continue to give my all to help Castleford Tigers reach the Grand Final."|
"The sale was agreed back in 2013 when the club had a real threat of going into administration and this decision was made to ensure we had financial stability at the club," Gill told the club website.
"We negotiated Daryl's services for this season as part of that sale and he has been an integral part of our success this season.
"The club would like to place on record our thanks to Daryl for his professional attitude and commitment this year and we wish him all the best for the future."
Castleford coach Daryl Powell added: "When I took on the job last season, the deal had already been done for Daryl to move to Warrington, which secured the future of the club at that time.
"Whilst we obviously don't want to lose our best players, this deal was in the best interests of the club."
Clark has scored 12 Super League tries this season and also touched down in their Challenge Cup final defeat by Leeds on Saturday, the club's first appearance at Wembley since 1992.
His arrival at Warrington offsets the imminent loss of joint-captain Michael Monaghan, who is to retire at the end of the campaign.
"Warrington are a massive club and have been involved in finals and massive games over the last few years," Clark told the Wolves' website. "As a player that's what you want to do within the game; win trophies, play in big games and finish high in the league every year and that's what Warrington have achieved.
"It feels like the right move for me to step forward."