Van Persie has been on holiday since helping the Netherlands to finish third at the World Cup in Brazil last month and will return to training on Monday.
He has sat out United's pre-season tour of the United States and he will also miss the club's final friendly against Valencia at Old Trafford.
New United boss van Gaal has also decided that he will not call on the 30-year-old for the visit of Swansea on the opening day of the Premier League campaign on August 16.
"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."
Meanwhile, van Gaal has questioned the merit of United playing friendlies during the season to make up for the absence of European football in the coming campaign.
He added: "We have discussed that already and have to wait and see if we have the chance to play matches but I think the first 10 weeks we have to train.
"After that it is different but it also depends on the opponent. It has to be a good opponent.
"At least in America it is a good tournament with good opposition."
Watch the International Champions Cup final between Manchester United and Liverpool live on Sky Sports 1 at 12.30am on Tuesday.