After sacking Brett Ratten, St Kilda president Andrew Bassat admits he regrets extending the coach's contract three months ago.
Ratten's departure - confirmed by the Saints on Friday morning - comes amid a review of the club's football operations.
The 51-year-old had signed a two-year contract extension on July 8.
"We gave Brett assurance at the start of 2022 we would give him clarity mid-year," Bassat said.
"At the time, the team was winning games and in contention, and we wanted to give Brett all the support he needed to give him the best chance of success and to show that he could be our long-term coach.
"If we as a club have regrets about that in hindsight, we cannot let those regrets get in the way of making the right decision for the future."
Ratten took over as caretaker coach midway through the 2019 season when Alan Richardson was sacked and has had three full seasons at the helm.
He led St Kilda to the finals in 2020, when the Saints won an elimination final against the Western Bulldogs.
But St Kilda have not made the top eight since then, finishing 10th in 2021 and 2022.
The Saints faded badly after a bright start this season, losing eight of 11 matches.
The club then started the review and the panel included David Noble, who was sacked as North Melbourne coach earlier this year.
Carlton also sacked Ratten as coach after the 2012 season.
St Kilda also announced on October 4 that veteran football administrator Geoff Walsh was taking over as their football manager.
It is understood that Walsh does not start until November 1.
The same day as his appointment, Walsh said in a radio interview that there's a "degree of irrelevance" about the Saints.
Melbourne assistant coach Adem Yze will be an early contender to take over from Ratten, while former St Kilda coach Ross Lyon will also be considered for a potential return.
Lyon took the Saints to grand finals in 2009 and 2010, and went close to ending the club's premiership drought.
The 55-year-old has not publicly indicated his interest in returning to Moorabbin.
St Kilda had a quiet trade period after missing out on Jordan De Goey, who decided to shun free agency following weeks of speculation about his future and stayed at Collingwood.
Ratten's departure comes amid significant off-field change at the Saints.
Walsh replaces Lethlean, who left the football department last month to become club chief executive.
Matt Finnis had announced earlier this year he was leaving that role and Lethlean was anointed as his replacement.
Ratten is the third senior coaching change this year and given his reappointment only 98 days ago, the most unexpected.
Essendon sacked Ben Rutten in a shambolic process and replaced him with Brad Scott.
Alastair Clarkson took over as North coach, although his start has been delayed by the fallout from the Hawthorn racism controversy.
Adam Kingsley also is the new GWS coach, following Leon Cameron's resignation earlier this year.
