Southampton sacked manager Ralph Hasenhuettl on Monday (Nov 7) after a poor start to the Premier League season that has left them in 18th place after six defeats in their last nine games.
"Hasenhuettl departs having made a significant contribution to the club," Southampton said in a statement. "However, we now believe it is an appropriate time to make a change.
Sunday's dismal display in their 4-1 home defeat by Newcastle United left the south-coast club languishing in the relegation zone after only three wins from 14 league games so far.
After four straight defeats, Southampton strung together a three-match unbeaten run before losing to Crystal Palace last weekend and needed to bounce back against Newcastle, but they were clearly second-best throughout the contest.
Scoring goals had also been a problem for Hasenhuettl's side this season, with their profligacy on display yet again against Newcastle, where the Austrian manager looked exasperated on the touchline and was left ruing missed opportunities.
Southampton has netted only 12 times in 14 matches. Only Nottingham Forest and Wolverhampton Wanderers, both also in the relegation zone, as well as 16th-placed Everton have scored fewer goals so far.
Hasenhuettl, who took over at St Mary's Stadium in Dec 2018, guided Southampton to an 11th-place finish in his first full season before finishing 15th in the next two campaigns.
He presided over two humiliating 9-0 defeats during his tenure, against Leicester City in 2019 and Manchester United in 2021.
"Everyone involved with the club would like to express their sincere thanks to Ralph for all of his efforts, as well as the unwavering commitment he has shown throughout his time as manager," the club added in its statement.
"First Team lead coach Ruben Selles will take charge of the side on an interim basis for our game on Wednesday night. The club will be announcing a permanent replacement in due course."