Ruben Amorim has been sacked as Manchester United manager 14 months after arriving at Old Trafford, the club announced on Monday.
United said in a statement that the Portuguese had left his role, with the club's leadership having "reluctantly made the decision that it is the right time to make a change".
The club added: "This will give the team the best opportunity of the highest possible Premier League finish.
"The club would like to thank Ruben for his contribution to the club and wishes him well for the future."
Current Under-18s coach Darren Fletcher will take charge of the team against Burnley on Wednesday.
United are currently sixth in the Premier League table after a 1-1 draw at Leeds on Sunday.
After that game, an irate Amorim stressed he was United's manager rather than just the coach during an eye-catching press conference in which he told the scouting department and director of football, Jason Wilcox, "to do their job".
The 40-year-old had alluded to frustration behind the scenes in the build-up to the match as the United boss refused to clarify his recent comments about the club's transfer plans.
He had looked downbeat when he sidestepped those questions but was more forthcoming when asked on Sunday if he still felt he had confidence from the board.
"Guys, to start with that -- and I noticed that you receive selective information about everything -- I came here to be the manager of Manchester United, not to be the coach of Manchester United," Amorim said. "And that is clear.
"I know that my name is not (Thomas) Tuchel, it's not (Antonio) Conte, it's not (Jose) Mourinho but I'm the manager of Manchester United.
"And it's going to be like this for 18 months or when the board decides to change, so that was my point.
"I want to finish with that. I'm not going to quit. I will do my job until another guy is coming here to replace me."
Amorim was appointed in November 2024 and led the team to the Europa League final in Bilbao in May, losing to Tottenham Hotspur, but they finished 15th in the Premier League last season.
His 14-month stint is the shortest reign of a permanent manager at United since David Moyes was sacked just eight months into his tenure in 2014.
United, 20-time English champions, have not won the Premier League since 2013, in Alex Ferguson's final season in charge.
