Salford have expressed surprise that Sean Long plans to combine a job on their coaching staff with a late conversion to playing rugby union.
The 35-year-old former St Helens and Great Britain scrum-half, who has never played union, has signed with Preston Grasshoppers and is scheduled to make his debut in the National League 2 fixture against Hull Ionians on 19 November.
"It's been an ambition of mine to play union and now seemed the right time," said Long, who retired after two injury-ruined seasons at Hull and took up a role at Salford.
Salford's director of football, Steve Simms, said: "We didn't know about it until yesterday. I think he just wants to have a bit of fun."
Grasshoppers' chairman, Michael Bailey, said: "Sean is a legend in rugby league and widely respected by fans of the union code. To have a player of his calibre in the team will bring a new-found confidence to our players."
Brian McDermott, who led Leeds to the Super League title last month, is on the three-man coaching shortlist at tonight's International Player of the Year awards at the Tower of London.