Fernandes struck from a direct free-kick to open the scoring before Declan Rice's equaliser for the Gunners in the second-half.
Amorim said afterwards: “I think he steps up all the time. Sometimes, he can show some frustration in some moments that can hurt him more than anybody. And I understand that, it’s that frustration: he wants to win.
"But, again, he's also always available, always there to play in different positions. And when we need sometimes a goal, a free kick, an assist, he’s always there. So I think he’s a very good example. He does some mistakes. that's normal, but he's a very good example for the other players.
“I think any coach when he wants to bring players, he expects the best, but sometimes they have to adapt and sometimes you have luck with the character of the player or not. Even with all the investigation that all the coaches do before signing players. What I can say is that we need more Brunos. That is clear.
"Not just the quality, the character, not some mistakes, but the character that he has, the availability in this league, is so important and he's so decisive with the ball and without the ball.”
Amorim also handed a United debut to young defender Ayden Heaven just weeks after his move from the Gunners.
He added, “Ayden’s so relaxed. He seems so relaxed that sometimes he's too relaxed. But I think we have a player there, so now we have to control and to tell him that was just the game, et cetera, et cetera."