Five defeats in Amorim's first 10 games is the worst record of any new United manager since Walter Crickmer, who stepped up from being club secretary in the 1930s.
Amorim said: "The manager of Manchester United can never, no matter what, be comfortable.
"You can argue I have been here one month and I've had four training (sessions), but we are not winning. That is the reality.
"I know that if we don't win, regardless if they pay the buyout or not, every manager is in danger.
"I like that because that is the job.
"It's part of football to have these difficult moments. I already knew it was going to be tough. You expect to win more games, to have players with more confidence to sell the idea and to work and improve things.
"At this moment it's really hard. We have to survive to have time and then to improve the team."