This afternoon, Amorim stated that Kobbie Mainoo is out of the game along with skipper Bruno Fernandes, who is set to miss the entire Christmas programme.
Asked about facing Newcastle with a depleted squad, the United manager began: "I am confident we can win any game.
"Of course, we have some problems but I believe in the team even without many players in this moment. I believe in the team and I believe that we can win any game.
"Of course, it is more difficult but, again, I trust in my players and if we are really focused in the game, we can win."
Given the issues in midfield, Amorim hinted that Jack Fletcher, after making his debut in defeat at Aston Villa, will have a bigger role on Friday night.
"We have other players, we need to maybe see different ways of playing. I think Jack Fletcher did a very good job, and that’s why when we have these opportunities, we need to give space to guys like Jack and the other ones."
Expanding on Fletcher and Shea Lacey making their debuts at Villa, Amorim said: "They are normal, they are good kids. The behaviour they have shown during this week are really good.
"I don't have the feeling that they were a little bit different because I played them for Manchester United. No, they are really focused, they are preparing for the game and they believe that they can play. That is a good feeling, so nothing different to what I saw in the last few weeks."
Amorim also confirmed Harry Maguire and Matthijs de Ligt won't make the game.
"We are still working with them, they are not available for this one. Let's see for the next one," he added.
Missing Fernandes
Meanwhile, regarding Fernandes' hamstring injury, Amorim admits he addressed the squad this morning to discuss the captain's absence. The midfielder isn't expected to be seen again until the final week of January.
"It is impossible to replace Bruno but I say that this morning to the team, I think we need to take the good thing if there is a good thing on that, that a lot of people need to step up.
"It is not just the creation, it is every set piece he is the guy who is organising the team and that is a good opportunity for everyone to step up and understand that we can't rely on one player for everything.
"Sometimes we rely on Bruno in the organisation, in the creation. We lost Bruno in set-pieces, we lost Bryan (Mbeumo) in those set-pieces, so this is massive for the team, but it is an opportunity for players to step up and to show the leadership we need in the team."
Asked about what they lose on the pitch without Fernandes, the manager continued:
"Everything. Everything because he understands every position on the field. He pays attention to every detail. Every set piece when you have a substitution, he is always the guy who is telling the other guys where they should be.
"But that is a very good opportunity for guys like Licha, Luke Shaw, all these guys. We need to have more leaders to step up because this can happen to Bruno; it is not usual, but this can happen, so it is a big opportunity for the other guys."
