Sale's Andy Powell will switch codes at the end of the season to join Super League side Wigan, according to Sharks director of rugby Steve Diamond.
Diamond had hoped to keep the 31-year-old Wales international forward, who has at the Salford City Stadium.
But he told BBC Radio Manchester: "Andy won't be with us next year.
"He's signed for Wigan for three years, although I don't know the in-depth details of the contract."
The Warriors, who are currently top of Super League, have yet to confirm any deal for Powell has been completed and declined to comment when contacted by BBC Radio Manchester on Tuesday.
Speaking after Sunday's victory against Wakefield, Wigan's assistant coach Iestyn Harris said: "I don't know anything about that. It would be great for Wales but, as for him coming to Wigan, I don't know anything."
Powell, who toured South Africa with the British and Irish Lions in 2009 and won the last of his 23 caps for Wales in February 2012, has played a key role in Sale's recent return to form.
They have moved off the bottom of the Premiership table and reached the final of the LV= Cup.
If the move is confirmed, he will follow in the footsteps of ex-Wales captain Gareth Thomas, who switched to rugby league in the latter stages of his career and signed for Crusaders in 2010.
Current Wigan centre Iain Thornley, who began his career in rugby league, spent two years playing for Sale before
Diamond added: "Andy's a good player and has been a good stalwart of Sale for the last couple of years.
"It was time for both parties to move away and, fortunately for Andy, he's got a contract now in rugby league that will see him through the remainder of his career."