It's been suggested Cunha is close to agreeing personal terms with United, which are prepared to pay the £62.5m buyout clause in his contract.
Ahead of their clash with Bournemouth on Sunday, Amorim said: "It's Manchester United.
"What I feel is that there's a lot of players that want to play for our club. I know that if you look at our club in the moment – with all the problems with the staff, people going, changing coach, the results – it looks like a little bit of a problem. But we have a clear idea.
"That is the easiest part to explain to a player. And then it's Manchester United. Everybody wants to play for Manchester United."
Asked if Cunha was on their list, Amorim replied: "I will not say anything about Matheus, because if I say one time I will have to say for any situation that is yes or no.
"So I will not comment about that. It’s hard to predict what is going to happen in the future."