Darren Williams has resigned from his posts as general manager, director of rugby and football manager at Hunslet.
Williams will step down on January 31 – the day when Hunslet take on Leeds in pre-season for the Harry Jepson OBE Memorial Trophy.
Hunslet chairman Neil Hampshire said: “There is absolutely no doubt that Darren will be a huge loss to Hunslet.
“He has been the backbone of the club for the last nine years and is hugely respected throughout the game by administrators, coaches and players alike. Knowledge and experience such as his is extremely difficult to replace.
“The club is currently looking at a new ownership model and, following a difficult last twelve months for the business – as well as changes in his personal life, having recently become engaged.
“Darren sees this as an opportune moment to step aside and allow the new regime to move Hunslet forward. It’s important that we support and respect that decision.”