Ricketts, who succeeded Scott Goodwin in December before guiding the Moatmen to safety and a 16th placed finish in EVO-STIK NPL First Division South, announced he was resigning for personal reasons on Monday.
In a statement on their website, officials said they hope to name their new manager as soon as possible and thanked the veteran striker, pictured, for his efforts.
A spokesman said: "The club would like to thank Gary for his contribution as player-manager and would like to wish him all the best for the future. A new manager will be appointed as soon as possible."
Former Hinckley United, Hucknall Town, Nuneaton Borough, Ilkeston FC and Mickleover Sports forward Ricketts joined the Moatmen in a playing role in October 2015 from Mickleover Sports.
The 40-year-old got off to a flying start with victory over his old club Mickleover booking a semi-final berth in the Derbyshire Senior Cup before five straight home wins in the league ignited hopes of a late run for the play-offs. Injuries, suspensions and availability issues kicking in by March saw a run of nine straight reverses end those dreams.
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