The Argentina winger started last night's Europa League win against Rangers.
Garnacho was selected amid interest from Chelsea and Napoli. But when asked if last night was the player's last appearance as a United player, Amorim replied: "No, I’m focused on the games and he’s here, he’s a player for Manchester United.
"Was really important for us today and let’s see in the next days.
"I think he’s improving in every aspect of the game. He was better today playing inside, also outside, changing positions, he’s improving the recovering position.
"You can see it until 90 minutes he’s always there recovering and helping, sometimes showing some frustration and that is good because he wants more.
"I think he has potential to be so much better in every situation in the game. What I can say is he understood what I was trying to do, was really clear, I just want to help them but in the end it’s them that do the job."