Luke Shaw is currently "not fit" enough to do what Louis van Gaal demands of him, with the Manchester United manager devising a special programme for the left-back to reach the levels required.

During training at Washington's FedExField in the run up to Tuesday's meeting with Internazionale, Shaw trained away from the squad – which was divided into two groups – with the £27m summer arrival asked to perform runs along the left flank before hitting crosses into the area.

Shaw then sat out large parts of the remainder of the session. Asked why, Van Gaal said: "He is OK, but I am always a trainer-coach who sees individuals and what they need. He needs to be fit and is not very fit and fit enough to do what I want. He needs to train individually until he is fit."

With Shaw having been with England at Brazil 2014 and starting training at Carrington less than a month after the tournament, Van Gaal would not be drawn on whether it was a surprise that the 19-year-old's fitness had dropped. "I cannot judge that, but I see what I see. I have spoken with him and we have made a programme for him. He agreed with me," said the Dutchman.

Van Gaal is not sure when Shaw will be fit enough again. "How long? That we have to see, but that I don't know," said Van Gaal. "I have heard good messages from Strud [Tony Strudwick, fitness coach] but we have to see."

Regarding Rafael da Silva, who has returned home with a groin problem, the United manager said: "You can leave the player in America and treat him here or choose to have the best treatment and we think it is much better at the Aon Complex. He can work out his jetlag much quicker if he goes home. There are two arguments for it and he agreed with me that he should go back. He is already back, but we will wait and see how long he takes."

Van Gaal added that Wilfried Zaha, the only player yet to kick a ball in anger on the summer tour of America, will play against Inter. “He will play in the second-half in the strikers’ position. When we play this system he has to play as a striker, otherwise he cannot play. Ashley Young is a winger, but he is another type who can play wing-back and he did very well against Roma. He can play left and right side, but we shall see. He can do the job. He believes me and he is now performing well."