Wigan Warriors chairman Ian Lenagan says scrum-half Matty Smith's move back to St Helens was only sanctioned after "much thought".
Wigan have confirmed that Smith is returning to St Helens on a three-year contract from next season, leaving Wigan after a successful four-and-a-half-year spell.
The England international racked up 139 appearances in that time for Wigan, scoring 22 tries, kicking 304 goals and amassing a club-record 25 drop-goals and Lenagan admitted letting him go was a difficult decision.
He said: "This was a particularly difficult decision for everyone involved and one that was made after much thought and consideration. St Helens approached Wigan earlier this year to discuss Matty's future and made it clear that they would be willing to offer him a long-term contract; an additional two years beyond that which Matty had remaining on his contract at Wigan.
"With George Williams firmly established as an important first team player and Thomas Leuluai re-joining the club shortly, together with the emergence of Jake Shorrocks and the cover that Sam Powell brings, we felt that the time was right in view of his tremendous service to Wigan for Matty to take up this new opportunity and secure his long-term future."
Saints head coach Keiron Cunningham says Smith's return to the club is a major boost as he believes the 29-year-old is close to being the complete player.
He said: "I'm delighted to have secured the services of Matty. He a class scrum-half who possesses a fantastic kicking and passing game as well as being an accomplished goal kicker.
"He has excellent leadership qualities and composure in big games after having experienced several over the course of his career.
"His partnership with Theo Fages will be an exciting one to watch."