Robin van Persie will miss Manchester United's first game of the season against Swansea City, Louis van Gaal has confirmed.
Van Persie, 30, will return to training on Monday having spent the last few weeks on holiday after helping Netherlands finish third in the World Cup in Brazil last month.
As a result, the Dutchman sat out of United's preseason tour of the United States and will not feature in the club's friendly against Valencia.
And in order to ensure the striker is fully prepared for the upcoming campaign, van Gaal will not call upon him for the visit of Swansea on the opening day of the season on 16 August.
"Robin will begin training on Monday but he won't play against Valencia, definitely not," said van Gaal. "He won't play in the Premier League either.
"When a player has been on holiday for three weeks they have to train.
"I'm sorry but players have to train and Robin needs a full training regime behind him before he can play again.
"People can criticise me for my decision but I know what to do with players who have had three weeks' holiday.
"Hopefully, Robin will get his fitness back very fast but, for now, he won't play.
"Robin wants to play every game, I know that, but so do the other 30 players in the squad."
United could also have another fitness concern ahead of the start of the new season after Danny Welbeck limped out of action during the 3-1 win over Real Madrid on Saturday.
The England international was replaced by Wilfried Zaha just before the end of the first half but his manager was unable to reveal the extent of the knock, telling reporters after the match: "We have to wait and see what the reaction is tomorrow."