Manuel Pellegrini has revealed that Sergio Aguero is one of four Manchester City players who are likely to miss the start of the season.
Aguero, Pablo Zabaleta, Martin Demichelis and Fernandinho were all given extra time off after playing in the Copa America, and they have not travelled with their club teammates for the pre-season tour.
Despite refusing to confirm that the quartet will be unavailable, Pellegrini has admitted that he is reluctant to rush them back too quickly.
"I think in football it's so important to work hard but also resting has the same importance," the City boss told reporters. "You have so many games throughout the year that if you don't give them 30 days after they've finished their internationals, it's very difficult for them to work hard.
"It's more difficult for the South American players because Pablo Zabaleta, Martin Demichelis, Sergio Aguero and Fernandinho finished later, the first days of July, so they won't have 30 days.
"I think when we return to Manchester they will start their pre-season. Maybe they will not be involved in the first game but I am sure they will work hard and will be involved as soon as they can."
City start the season with a trip to West Bromwich Albion on August 10 before hosting Chelsea six days later.