Mark Hughes has been sacked as Southampton manager after eight months in charge.
The Saints, who drew with Manchester United in the Premier League on Saturday, are 18th in the table.
Southampton confirmed the move in a statement, adding: "The search for a new manager to take the club forward is already under way."
First-team assistant coach Kelvin Davis will take charge of the team for the game against Tottenham on Wednesday.
BBC Sport understands Southampton are set to approach former RB Leipzig manager Ralph Hasenhuttl about the manager's job. The 51-year-old Austrian has been out of work since leaving Leipzig in May.
The club were one point above the relegation zone at the time and the 55-year-old led them to safety last season by securing two wins from their last four games.
However, they have struggled again this season and, across his spell, have won just three of their 22 league games.
Before the draw against Manchester United, Southampton were beaten 3-2 by relegation rivals Fulham and knocked out of the EFL Cup on penalties by Leicester.
Along with Hughes, assistant first-team manager Mark Bowen and coach Eddie Niedzwiecki have also left the club.
Phil McNulty, BBC Sport chief football writer
Southampton's hierarchy were never going to make the same mistake as last season when they almost left it too late to sack Mauricio Pellegrino as they dropped towards relegation.
It meant added pressure on Mark Hughes, who presided over their survival, and his dismal win record of three wins from 22 league games made this decision inevitable.
Hughes has told regular hard luck stories this season but eventually the script becomes tired when performances, even though they were decent enough on occasions, simply do not get results.
Hindsight is a wonderful thing but Southampton may now reflect on their decision to give Hughes a three-year contract in the afterglow of retaining their Premier League status, rather than thanking him for his efforts and returning to the drawing board.
Saints' vice-chairman Les Reed and technical director Martin Hunter have already gone and the sweep has continued with Hughes' sacking. These are changing times at St Mary's.
As for Hughes, it is hard to see where he will go next after successive sackings at Stoke and Southampton in so short a time.
He now joins other old managerial heads like Sam Allardyce, David Moyes and Alan Pardew on the margins.
'Saints board only ones left to blame'
Adam Blackmore, sports editor of BBC Radio Solent, said Hughes "has paid the price for results", but he added "the problems that are afflicting Southampton at the moment cannot all be laid at his door".
"The football of late has been improving but individual defensive mistakes have riddled the season, and that opens up the whole debate about bad recruitment over a period of two years now," he explained.
"Hughes did well to keep them up last season, but after a summer of making signings that have deepened the squad, not improved the team, Saints have effectively damaged themselves by losing their golden touch in the transfer market, and not adding match-winners to a squad who narrowly avoided relegation last season.
"Saints fans have been crying out for a return to the high-tempo, high-pressing game that saw them get great success under Mauricio Pochettino and Ronald Koeman, and if as expected they appoint Ralph Hasenhuttl, the 'Alpen Klopp', later this week, they may get their wish.
"The Saints board need to get this one right, because from now, they themselves are the only ones left to blame for the club's current state."
|Mark Hughes record in the Premier League|
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