Worcestershire chief executive Matt Rawnsley has stepped down from his role and has left "with immediate effect".
The 43-year-old former Pears spinner left his job as managing director of an industrial and aerospace components manufacturer to return to New Road as CEO in March 2018.
Worcestershire won the T20 Blast in 2018 and reached the final again this year but struggled in red ball cricket.
They have now reorganised their structure to cope with Rawnsley's exit.
A club statement said: "In the interim, all matters will be handled by the board, and should be directed to chairman Fanos Hira.
"All cricket matters will continue to be handled by the cricket steering group which is chaired by vice-chairman Paul Pridgeon.
"The board would like to thank Matt for all his hard work in the last 20 months and wish him every success in the future."
Pridgeon, who also played for Worcestershire from 1972 to 1989, has become an increasing presence since returning to New Road on a regular basis following his long-standing role as head of cricket at Shrewsbury School, with whom he unearthed a succession of talented signings for his old county.
Worcestershire's eighth-placed finish in the County Championship in 2019 was their worst since two-division cricket began in 2000.