Van Persie, 30, did not travel with United on their pre-season tour of the United States, and will not appear in the final friendly against Valencia at Old Trafford on 12 August, four days before their first league match.
Manager Louis van Gaal said his compatriot would resume training on Monday and, having missed much of last season through injury, would not be rushed back into the team before he reached full fitness.
"When a player has been on holiday for three weeks they have to train," Van Gaal was reported as saying by British media.
"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."