Jose Mourinho has revealed that some of his players are "not ready" for Chelsea's trip to Burnley for their Premier League opener on Monday night.
Brazil trio Oscar, Willian and Ramires, Belgian pair Eden Hazard and Thibaut Courtois, and Germany's Andre Schurrle have all missed the majority of Chelsea's pre-season preparations after featuring at this summer's World Cup.
"Are they ready individually? No," BBC Sport quotes the Blues boss as saying.
"But we have to be ready as a team for Monday. Can it be a team of six guys not ready? No.
"This is modern football. It's going in this tendency - more matches, more competitions, less time to work, even not enough time to have a real holiday for bodies and brains that top football players need. There's not enough time."
Arsenal manager Arsene Wenger has also criticised the hectic schedule faced by players plying their trade in England.