The Chilean said he lost confidence under the former club coach despite claiming that the Portuguese was one of the best coaches in the world
Alexis Sanchez stated that the former Manchester United manager Jose Mourinho has created an unhealthy atmosphere at Old Trafford.
Mourinho was fired in December and replaced by head of caretaker Ole Gunnar Solskjaer among the news of unrest in United's dressing rooms.
Sanchez was attracted by Mourinho's Premier League rivals Arsenal to United in January of last year, however, the 30-year-old striker fell into disgrace before the Portuguese's departure.
The Chile national Sanchez – who has only scored five goals in all competitions since arriving in Manchester – said he had lost confidence under Mourinho.
"Mourinho is one of the best coaches in the world, as a coach, as he studies videos, how he goes about things," said Sanchez al BBC .
"But inside the group there was that feeling that you were on the team, then outside, sometimes I did not play, then I did, then I did not and as a player I lost the confidence.
"Then an atmosphere was created that was not healthy."
Sanchez, who is in doubt for the fifth round of the United FA Cup at Chelsea, added: "I've played football since I was five and if I was taken off the ball, it's like I lose my joy."
This will help you survive on a football weekend without #MUFC !
– Manchester United (@ManUtd) February 16, 2019
The attacker also struggled with the provisional boss Ole Gunnar Solskjaer, with the current boss who said he "can not do anything against Alexis" and that the thirty year old needs to "find himself".
The article continues below
Should he be fit, Sanchez could play an important role for the club in the coming weeks, with Anthony Martial and Jesse Lingard destined to lose their next matches with Chelsea and Liverpool because of an injury.
And while Solskjaer believes there will be a chance for the former star of Arsenal to show his best, he also hinted at giving young Tahith Chong and Angel Gomes the opportunity to show their worth.
In addition to Chelsea and Liverpool, Manchester United will also face Crystal Palace and Southampton before going to France for the return leg in the Champions League last 16 against Paris Saint-Germain.