The 18-year-old made his debut in the Europa League against Real Sociedad last week, having finally joined up with the Red Devils last month after a move from Atalanta for an initial £18 million.
James is also thriving on the competition for places, having inspired the recent win over Newcastle, but the former Swansea star has detailed how impressive Amad has been each day in training.
“Amad has come in and, as a young lad, he’s been unbelievable in training,” James told the United Review.
“I mean his professionalism [is very good] and he’s settled in straight away, I’d say, do you know what I mean?
“We see his quality in training, he has unbelievable feet, but we’ve seen he also presses well and wins the ball back, which is exactly what we want.”
James has also discussed the state of play heading into the second leg of the round of 32 tie against La Real in the Europa League, with United carrying a 4-0 lead.
“I think, whenever I get called upon, I must always be ready,” James added. “We made a lot of breaks and that is how we got the goals.
“Obviously it’s not over yet as they have still got to come to us, but we will go into the game with the same attitude as we did for the away tie.”