Moyes won the Europa Conference League in his time at West Ham and has collected four wins in six games since replacing Sean Dyche to see the Toffees move 13 points clear of the relegation zone.
Such has been Everton’s improvement, they go into the game above United in 15th place.
Asked what makes Everton difficult to play, Amorim replied: “Confidence. The way they play, they believe it a lot and are winning games, being really competitive, so it is an amazing job by David Moyes to recover the team.
“You feel it, when you watch the game you feel the confidence and belief is there. It is going to be a really hard game.”
Moyes lasted only eight months at Old Trafford after replacing the legendary Ferguson at Old Trafford over a decade ago.
“It shows it is a difficult job,” said Amorim. “But we have to try to understand the history. This club had a figure that you cannot replace in Sir Alex Ferguson and then it is a hard job to do it.
“Everything was connected with one person. When that person leaves, it is really hard. He is doing an amazing job and did do an amazing job at West Ham, and is a coach that is hard to win games [against].”
