Sale forward Andy Powell is to switch codes this summer and join the Wigan Warriors on a three-year contract.
Sharks director of rugby Steve Diamond admitted that his attempts to persuade the 31-year-old Wales international forward to stay at the Salford City Stadium had failed.
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."
Wigan have yet to confirm the deal; assistant coach Iestyn Harris, speaking on Sunday, 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."
Warriors chairman Ian Lenagan added: "Sale can talk about their players as much as they want, but I am not going to comment on their comments."
Powell, who toured South Africa with the British and Irish Lions in 2009, won the last of his 23 caps for Wales in February 2012.
Will Andy Powell prove a success in Rugby League?