Ex-Hull FC and Cronulla Sharks half-back Brett Seymour will take temporary charge of Whitehaven following Steve Deakin's resignation.
The 30-year-old Australian, who joined Haven in 2014 following his release by Castleford, is at the helm for Sunday's Championship opener against Halifax.
Deakin, who left for family reasons, was appointed in September 2014.
A club statement said: "We'd like to thank Steve for the outstanding level of commitment he has given pre-season."
Haven brought former Barrow and Oldham coach Deakin back to Cumbria after a successful stint with the Catalans Dragons reserve side St Esteve XIII.