Amorim and United face Fiorentina today in their latest preseason friendly.
He wrote in today's match programme notes: “Welcome back to Old Trafford for our final pre-season game of the summer before the Premier League resumes next weekend.
“This is such an important time of year, not just to build up towards match fitness, but especially to take advantage of time together, on and off the training pitch, to develop as a group.
“I can feel the improvements in the environment now that the right details are in place to help us all to be better. The players we worked with last season are looking stronger, and we have made some important additions to the squad.
“Bryan (Mbeumo) and Matheus (Cunha) are top-class players who have proven their qualities in the Premier League, but they are also really humble and showed a huge desire to come to Manchester United. Diego (Leon), is of course, a different type of signing, with high potential for the future.
“We can all see that the confidence in the group is growing, and we feel like a different team already. We must always remind ourselves how special it is to be Manchester United, and how that means producing the highest standards in everything we do.
“That includes occasions like today, as we welcome Stefano Pioli and Fiorentina to Manchester. We must strive for our best levels every day, because doing so consistently is the only way to set the right standard for this club.”