"The regression of the team led by the manager may be the immediate trigger for today's action, it is also the result of some poor decisions", the Manchester United Supporters' Trust said.
While his success in the commercial market has taken the club to new heights on the balance sheet, the football side of the business has been a train wreck by Manchester United's standards under his watch.
His departure from Old Trafford came a day after the third anniversary of his sacking from a second spell at Chelsea just six months after winning the title with the Blues. Mourinho had a habit of holding up three fingers in front of reporters and fans to remind them of his three Premier League championships.
May 27, 2016 - Appointed as Manchester United manager, replacing Louis van Gaal.
February 26, 2017 - Ibrahimovic scores twice as the Red Devils beat Southampton 3-2 to lift the EFL Cup - Mourinho becomes the first United manager to win silverware in his debut season at the club.
2:15 Jamie Carragher discusses why Manchester United sacked Jose Mourinho
With the Portuguese gone, United may make their move for the Spurs boss, who has taken his club to consecutive top-three finishes but has yet to bring a trophy to North London.
Defeat to Liverpool over the weekend seemed to be the final straw, with United delivering a negative performance that summed up their slow start to the season. However, you get the feeling that anyone other than Mourinho would do at the moment.
The wound went even deeper for Mourinho as City are managed by Pep Guardiola, who got the better of him when he was in charge at Barcelona and Mourinho was at Real Madrid. Mourinho routinely dropped the club's most expensive ever signing, £89 million ($113 million) midfielder Paul Pogba, to start a power struggle he has ultimately lost.
After 17 games, United do not have a positive goal difference. Flush with cash from Abu Dhabi - albeit with financial practices under scrutiny by football authorities - City finished 19 points ahead of United.
"I feel the same as when I arrived here to work as a coach, and further back as a player", Solari continued.
The club said in a statement he had left with immediate effect.More news: Jürgen Klopp's reaction to Liverpool v Bayern Munich CL draw
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