The 38 year old has another year on his playing contract with the Millers and will continue to work on his fitness role while helping youth players making the move into the reserve team.
Boss ndy Scott told the official website; "I have spoken to Warney about his role, He still has a playing contract and we have plans for him to work on the fitness side and to have a more active role with the reserves as well."
"He still has something to contribute as player, certainly with the reserves helping the young players coming through. We want to establish more youth team players in the reserves next year and have a better link with the first team, and Warney will have a big part to play with that." he added.