Motherwell vowed to move quickly to replace Stephen Robinson after their manager declared he had taken them as far as he could and resigned.
Robinson quit after a 2-0 home defeat by Kilmarnock left Motherwell without a win in nine matches and in 10th place, two points above Scottish Premiership bottom club Hamilton - their opponents on Saturday.
Keith Lasley will be in charge for the Lanarkshire derby and the long-serving former skipper is a strong contender to succeed Robinson, while former St Johnstone manager Tommy Wright was quickly installed as bookmakers' favourite.
Motherwell revealed Robinson had approached the board after Wednesday's defeat, giving an "honest assessment" of their situation and "stated his desire to leave".
A club statement added: "It is with regret that the board accepted his resignation, having carefully considered his reasons for wanting to leave his post.
"Despite the current restrictions, the board will now run a thorough process to identify the right person to take the manager's post.
"This will move at pace, mindful of the busy fixture list and the January transfer window's impending opening."
Robinson will be a hard act to follow. A former assistant to Ian Baraclough and Mark McGhee, he steered the club away from relegation danger after taking over for the final 12 games of the 2016-17 season.
The former Oldham boss then led Motherwell to two cup finals, two comfortable mid-table finishes followed by a third-place position and a return to Europe.
His record at developing players was highly impressive with the likes of David Turnbull, Louis Moult, Cedric Kipre, James Scott and Jake Hastie bringing in more than £6million in transfer income.
Those achievements put the Northern Irishman on the shortlist to take over his country in the summer but Baraclough got the job instead and Motherwell will not get any compensation for his departure months later.
The 46-year-old thanked the club for their support and listed the achievements of himself and his staff, before adding: "We cleared the club's external debt through player sales, cup runs and league positions. The club has numerous assets going forward, and I'm sure that they will have a strong finish to the season with the brilliant coaching staff currently there.
"My goal was always to leave the club in a healthier position. I believe the staff and I have done this.
"I now feel it is the time for someone new to take the club forward as I feel I have taken it as far as I can."
Chairman Jim McMahon hailed Robinson for delivering or exceeding targets each year with his transfer record ensuring the club were in a "strong financial position".
"It has been a privilege to work with him over these years," he added. "We all wish him well for the future."
Motherwell were in the top six a week ago before, temporarily at least, losing six points after St Mirren and Kilmarnock appealed against punishments for breaching Covid-19 rules.
They were seconds away from beating Dundee United on Saturday and they dominated the majority of the first half against Killie.
But an ongoing struggle to capitalise on chances and possession cost them and they are yet to score an equaliser this season, and looked well beaten after losing a second goal and Mark O'Hara to a red card.
Speaking soon after the match, Robinson accepted the blame.
"Players aren't playing at the top of their game, simple as that, and I have to look in the mirror because it's my fault: I'm the one that picks the team, I'm the one that signs the players," said Robinson, who also admitted coming up against obstacles in his hunt for new signings.
"So hopefully I will be the one that takes the stick and not them.
"I hope they care as much as myself and the staff, Keith and Craig (Hinchliffe) and Mo (Ross), and Rossco (Ross Clarkson), the analyst, with the hours they put in. I hope they care as much as we do because we genuinely care about this football club.
"I hope some of them look in the mirror because they owe a lot more than they are giving.
"Everyone needs to look in the mirror, and that includes me. I will do that and make sure my message is right and what I'm doing is right. And, if it's not, then ultimately I will be the one that decides it."