Luke Shaw has been training alone during Manchester United's preseason tour after coach Louis van Gaal decided that his fitness was not at the required standard.
Van Gaal told reporters that England defender Shaw had returned from the World Cup unfit for Premier League action.
The 19-year-old left-back trained away from the rest of the squad at Washington Redskins' FedEx Field stadium as United prepared to play their third summer fixture in the U.S. against Inter Milan on Tuesday evening.
Asked why Shaw had been told to work alone, Van Gaal said: "I am always a trainer who sees the individuals and what each player needs.
"Luke needs to be fit, and he's not very fit and can't perform how I want. He needs to be fit and to train individually.
"I can't judge why. I see what I see. I have spoken with him and we have made a programme with him. He has agreed. We will have to see how long it takes. I don't know.
"I have heard good messages from Tony Strudwick, the fitness coach."
Key European club fixtures
French Ligue 1 -- Aug. 8
FA Community Shield: Manchester City vs. Arsenal -- Aug. 10
German Super Cup: Borussia Dortmund vs. Bayern Munich -- Aug. 13
English Premier League -- Aug. 16
Spanish Super Cup: Real Madrid vs. Atletico Madrid -- Aug. 19 and 22
Spanish La Liga/German Bundesliga -- Aug. 23
Italian Serie A -- Aug. 30
Shaw's fellow England players Wayne Rooney, Danny Welbeck and Phil Jones are all considered to be ahead of Shaw in the fitness stakes, and worked with the main squad ahead of the Inter game.
Meanwhile, Van Gaal said he would look to switch another of United's youngsters, winger Wilfried Zaha, into a more advanced role in order to fit him into his 3-5-2 system.
The coach added: "He will have to play as a striker as he can't play the other positions in the system. Ashley Young can play as a wing-back but Zaha cannot do that, so he will be a striker.
"I have spoken with him and I think he can do it. We will see. He will play the second 45 minutes of this game and will play as a striker."
Van Gaal, who believes he inherited a "broken squad" from David Moyes, also dismissed rumours that Javier Hernandez was on his way to Inter.
"I don't know anything about that," he said. "You would need to wait for an announcement from us, but I can't say anything about that."