Sanchez, 31, has opened up about his nightmare spell at Old Trafford in an extraordinary rant.
The Chilean winger moved to United in a swap deal for Henrikh Mhkitaryan in January 2018.
He was on a bumper £500,000-a-week contract but scored just five goals in 45 appearances before sealing a loan switch to Inter Milan - a transfer which he eventually made permanent.
And Sanchez has sensationally claimed he wanted to terminate his United contract and return to North London after one training session with his new team.
In a video posted online, he said: "I want to tell you about my period at United, about many things that were said and that made me look bad.
"I got the opportunity to go to United and it seemed tempting to me. It was something nice for me, because when I was a kid I liked that club a lot.
"I ended up signing without much information about what was happening in the move. The first days that I was with my colleagues, sometimes there are things that you do not realise until you arrive.
"The first training I had I realised many things. home and I told my representative: 'Can't the contract be terminated to return to Arsenal?'
"They start laughing and I told them that something did not sit right with me. It had already been signed."
Sanchez continued by recalling one moment under Jose Mourinho which left him "very sad."
He said: "In a game with West Ham I wasn't picked. That had never happened to me as a player. It bothered me and I said it couldn't be possible.
"To go from being one of the best in the Premier League to not playing in five months. I came to my house and I was very sad. The next day I trained in a double shift, because I love what I do."
United lost the game to West Ham and Mourinho was sacked a few months later with Ole Gunnar Solskjaer replacing the Portuguese.
And Sanchez spoke to Solskjaer about securing a move away from Manchester.
"Then the next coach arrived, the current one, and I decided to talk to him. I told him that I needed to take a breather, and the opportunity to go to Inter. He told me that yes, there was no problem," he added.
"Journalists spoke without knowing and it bothered me, it hurt. Former players spoke who had no idea of anything that was happening inside the club and gave their opinion damaging you, that it was your fault.
"Since they had to blame one, they blamed me."
Sanchez ended the outburst by saying it bothers him things didn't work out.
"I only have words of thanks to United for giving me the opportunity to defend the shirt. It bothered me that things did not go the way I wanted.
"If the atmosphere had been more positive, it would have turned out differently. I tell it all now because I have already passed a period of learning as a player and a person. I would have liked to win everything."
Featured Image Credit: Instagram/PA
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