What you need to know:
- Former midfielder Michael Carrick, who was part of Solskjaer's coaching team, will take charge for a crucial Champions League clash away to Villarreal on Tuesday.
- Another defeat in Spain would leave the Red Devils needing both results in the final round of matches in Group F to go their way to avoid crashing out at the group stages for a second consecutive season.
Manchester United ended Ole Gunnar Solskjaer's three-year reign as manager at Old Trafford on Sunday, but plan to wait until the end of the season to name the Norwegian's permanent successor.
Saturday's 4-1 embarrassment at the hands of struggling Watford was the final straw for the United board, who had stuck by Solskjaer in recent weeks despite humiliating home defeats to Liverpool and Manchester City.
Former midfielder Michael Carrick, who was part of Solskjaer's coaching team, will take charge of the forthcoming games while the club look to appoint an interim manager till the end of the season.
"Manchester United announces that Ole Gunnar Solskjaer has left his role as Manager," the club said in a statement.
"Ole will always be a legend at Manchester United and it is with regret that we have reached this difficult decision. While the past few weeks have been disappointing, they should not obscure all the work he has done over the past three years to rebuild the foundations for long-term success."
Solskjaer leaves with United already realistically out of the Premier League title race, 12 points behind leaders Chelsea down in seventh in the table, and having exited the League Cup.
Carrick's first game in charge will be a crucial Champions League trip to Villarreal on Tuesday.
Another defeat in Spain would leave the Red Devils needing both results in the final round of matches in Group F to go their way to avoid crashing out at the group stage for a second consecutive season.
A run of five defeats in Solskjaer's final seven league games contrasts sharply with the anticipation that surrounded the club in August when Cristiano Ronaldo made a surprise return to Old Trafford in the final days of the transfer window.
United also spent over £100 million ($134 million) on Jadon Sancho and Raphael Varane as they looked to build on finishing second in the league to Manchester City last season.
However, Solskjaer was unable to assemble the pieces of his star-studded squad into a collective unit despite Ronaldo's return of nine goals in 14 games.
"We don't know what to do with the ball, we don't know how to defend properly and we're conceding a lot of goals," said United goalkeeper David de Gea, whose double penalty save from Watford's Ismaila Sarr counted for nothing.
"It's not acceptable for this club and the level of players that we have. It's another nightmare."
Solskjaer had ridden out storms before in a rollercoaster but ultimately trophyless three years.
However, even his credit as a club legend for scoring the winning goal in the 1999 Champions League final to win a historic treble for Alex Ferguson's side was fading as he was booed by the travelling support at Vicarage Road.
"Thank you Ole. You did us proud," said former United captain Gary Neville, who has been criticised for not calling for his former teammate to be sacked in his punditry.
"The last two months were tough but before that you restored some soul into the club."
Zinedine Zidane, who won three Champions League titles with Ronaldo and Varane at Real Madrid, is the bookmakers' favourite to succeed Solskjaer, with Leicester manager Brendan Rodgers and Ajax boss Erik ten Hag also in contention.
But the decision to wait until the summer to make a permanent appointment could open up a wider pool of potential candidates, including Paris Saint-Germain boss Mauricio Pochettino, who has previously been linked with the job.