The 27-year-old fuelled speculation by admitting he was "ready for a new challenge" in a midweek interview, meaning the England international remained a hot topic ahead of the Boxing Day trip to Wolves.
"Normal situation," Amorim said. "When I feel that it's the right moment I will change something. Until then I will continue to think what is the best for the team.
"I speak with him every day. Not about the interview, about the performance."
Amorim confirmed that Rashford "wants to play, he is trying" but "it's my decision, only my decision".
"I spoke with a lot of players - individually, during training - so I'm trying to do things... I am doing things my way," the recently appointed head coach said. "And it's the only way I know.
"If I don't do that I will lose myself and I will not lose myself. I know what I'm doing."
Amorim questioned the "choices" of people surrounding Rashford after leaving him out against Bournemouth, when Gary Neville said the forward leaving felt like an "inevitable ending".
The former United captain also called it a "distraction for the manager" - something the Portuguese denied.
"No, I don't think so," Amorim said. "Not for me, not for the other players because everybody is there every day during training, so they understand and that is the key point.
image [https://cdn.magzter.com/1583575389/1735192288/articles/yIe70l4CB1ytwELQJkcrlO/5p2Ghs7i81735208486881.jpg]
"For the media and for the other people, I cannot control that. But I'm really focused and they know, I'm so clear in my message, everybody in Carrington know what I'm talking about and what I want from Marcus and everybody else.
"So, it's not a distraction for us. Maybe it's for the media but that is not my concern."
Asked to clarify what he would like to see from Rashford, he said: "Like any other player, the best that they can be.
"If you have big talents, performance, big big responsibility, big engagement, like push forward everybody in this moment. And some guys ...