Erik ten Hag has no players during the international break.
The Dutch manager has won five of his eight games for Man United this campaign and their last game against Liverpool was postponed before the international break.
The Red Devils return to action on 2 October against Manchester City and have a period of over two weeks without any football matches to play.
He could have used the break to make the team more familiar with his tactics but most of his players are away representing their nations.
“I don’t have the players. What can we plan?” Ten hag told the club’s official website.
“We can plan work structures with the players who will be there. They will get a break but also have good sessions,” he added: “We can work on specifics but, when 90 per cent of the squad is not there, we cannot work on development. That is clear.”