Ruben Amorim insists it would have been unfair on Ruud van Nistelrooy to have kept him on the backroom staff at Manchester United.

Van Nistelrooy took caretaker charge for four games after Erik ten Hag was sacked in October, overseeing three wins and a draw before Amorim arrived in Manchester.

Amorim let Van Nistelrooy go on his first day at United after speaking to the Dutchman, who was keen to stay on and assist the 40-year-old. Amorim brought assistant manager Carlos Fernandes, first team coaches Adelio Candido and Emanuel Ferro, fitness coach Paulo Barreira, goalkeeping coach Jorge Vital and analyst Eduardo Rosalino with him to United. Van Nistelrooy is now the manager of Leicester City and will return to Old Trafford in the FA Cup fourth round on Friday night.

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"It was not a difficult situation," Amorim said, "because it was so clear for me. I just had to explain. I think it is really simple.

"He understands, he is a man of football, he understands this situation. I have my team and my staff. I could keep Ruud because it was a good thing for me, a popular thing to do. But I will not put Ruud in front of my guys, no matter what, and then I had to put a person like Ruud in the end of the hierarchy on my staff, and I think that was not fair on Ruud.

"To show respect to Ruud, I was really clear with him. I explained I have my team and I will continue the same way and I will not put a guy like Ruud, a legend of this club, in the end of the hierarchy in the staff. So was the clear decision, really simple to explain and he took it like a class guy as he is.

"The most important thing to have as a coach is to have a staff who understand the way you want to play, the standards you have. And when I say standards I am not saying Ruud doesn't have these standards. He was a legend of this club, he knows what it takes to win, but I prefer to work with a team that brought me here.

"It’s clear that is important for me, to explain the same things to the players. I’m really comfortable and confident that I know how to win, no matter the club.

"Of course, we are losing and you need experienced guys. But I’m not lost, or I feel a [lack] of something in the staff. We just need to improve as a team."

Amorim has lost eight of his 19 matches since he took over from Van Nistelrooy and has a win percentage of 42.11. Amorim admitted last month how unflattering it was for him that his record this season is worse than permanent predecessor Erik ten Hag, who suffered four defeats in the first 14 games of the campaign.

"It’s not awkward," Amorim said of Van Nistelrooy's unbeaten record. "I think it’s normal. He knew the team, he worked with the team. I made some decisions that are really hard, to sometimes create problems, friction in the team.

"Everything in the schedule that you don’t have time to train, to know the person. It’s really hard because I’m a really proud guy, but I take this normally. They were better than me in training this team, so I’m trying to help them see the game the way I see, to improve the performance, and also the results.

"It’s really hard, just the way we are sometimes losing. I understand we had a lot of games without training but, even then, in that context, I feel we should do better.

"When you are a coach, you want to win games and have that feeling of winning, to cope with everything when you have these problems. Of course you have difficult moments, hard to sleep, whatever.

"One good thing I learn in this moment is that even in the good or bad moments, my idea is so clear, that I make the same decisions without any other concerns. I just want to help the team to win and change things."

Amorim admitted he has doubted himself during United's struggles but that he also did during his winning runs with Sporting. "Even when you are winning, you doubt yourself. That is a good thing. I am always doubting myself, about everything. Even when I was winning all the games in Portugal, so it’s the same situation.

"The part is to lose, to fail, you can say it, to fail to my players, not helping them. Seeing them suffer every time, especially at home. But it’s clear to me what we need, what profiles we need.

"Even if it is a left foot or a right foot in this position, what the characteristics are. It is so clear to me that until the last day I will continue to take this job in the same way."