RIO DE JANEIRO (AP) ― Elite professional footballers may be pampered like royalty, but near constant training and grueling club and country commitments are taking their toll on the World Cup before the tournament even kicks off in Brazil.

Germany midfielder Marco Reus on Saturday became the latest player to pull out of the global football showcase, joining the likes of Frank Ribery, Radamel Falcao, Theo Walcott and several other big names who will be watching the World Cup in between trips to the doctor or physio.

Dutch coach Raymond Verheijen, who has in the past helped condition Netherlands, South Korean and Russian players for European Championships and World Cups, has long been a critic of over-training and blamed it for increasing injuries.

He said national coaches need to wind back the amount of training they put their squads through at the end of long club seasons.

“Their players are still fit, but they are tired,” he told the Associated Press in a telephone interview. “Players have to rest. It’s the opposite of club preparations at the start of a season.”

He called the intensive training regimes of many national coaches “Russian roulette,” saying that overtraining is a key cause of muscle injuries.

Football is, of course, a fast and physical sport and not all injuries can be attributed to exhaustion, but many of the stars at the World Cup had barely finished their club seasons when they had to report to rigorous national training camps. Any lingering aches and pains they accumulated have no time to recover.

Former Sunderland manager Paolo Di Canio told Gazetta dello Sport that England’s campaign in the strength-sapping heat of Brazil will likely suffer due to the Premier League’s non-stop season.

“They do not have a winter break,” Di Canio said.

“It’s nice to play at Christmas, but they pay the price for this in June when the fatigue can be devastating.”