Canterbury have sacked Des Hasler just five months after agreeing to a contract extension.
Hasler has been at the helm of the Bulldogs since 2012 and guided the side into the finals in every one of those seasons save for this one.
The club is now looking for a new coach, a new captain, following James Graham's departure to St George Illawarra - while there isn't a CEO at the helm until NRL official Andrew Hill begins at the completion of the World Cup.
"Today, I informed Des Hasler and his management of our decision to pursue a new head coach for our club, effective immediately," said Bulldogs chairman Ray Dib.
"The heads of agreement reached with Des Hasler for an extension of his contract were non-binding and a decision has been made not to renew his contract for next year.
"These types of conversations are never easy, especially when they involve people we respect personally and professionally, however, the club believes the decision to change our football leadership was absolutely necessary.”
It's understood Dib had completed a two-day review of the team's football department last week, which included speaking to just three senior players.
It's also believed he has kept incoming half Kieran Foran abreast of the situation, given his close links to Hasler while at Manly. It's not thought that Foran has a get-out clause in his contract if Hasler isn't at the club.
"The club will now begin its search for a new head coach and will provide further information once that process has been completed," Dib said.
Canberra assistant Dean Pay is the favourite to take over from Hasler, while current assistant Jim Dymock has also indicated he is keen on the role.
Former South Sydney coach Michael Maguire is also likely to come into contention, along with Todd Payten.
The decision could also open the door for Des Hasler to coach the NSW State of Origin team next year, having worked with the Blues as an assistant before landing the top job at Manly in 2004.
Hasler's 2017 season marked the first time he had missed the finals since his rookie year as a head coach, while he took Canterbury to grand finals in 2012 and 2014.