The new boss spoke to club media at Carrington on Friday afternoon, shortly after addressing a packed room of journalists in his opening press conference.
Ruben discussed the squad's overall fitness and the availability of Luke Shaw, plus the need to manage different players' workloads.
"We have to see; we have one more training," Amorim told Mark Sullivan.
"But Luke [Shaw], for example, is feeling fine, but we have to build his fitness during games, so we have to be careful. I think he’s a very good player, so I will take care of him and I want these kinds of players that are important in our squad for a long period and not just for a game.