Manchester United manager David Moyes has been accused of "gambling" with the fitness of Robin van Persie by Dutch coach Raymond Verheijen.
Despite having scored seven goals in his 11 Premier League appearances this season, the Dutch striker has struggled to fully recover from long-term groin and toe injuries.
As a result, Van Persie has just started one game since his side's 1-0 win over Arsenal in early November, against Newcastle earlier this month in a game where the 30-year-old visibly struggled.
Sidelined for the rest of the month with a thigh strain, Van Persie's woes are a direct result of conditioning mismanagement and "prehistoric" training regimes, according to former Wales assistant manager Verheijen.
"Coincidentally when United were in Sydney last July, I was there as well," Verheijen told Irish radio station News Talk on their Off The Ball show.
"I went to the training sessions and I could see what they were doing with Robin van Persie. He had to do a lot of running work and sometimes he even had to do it twice a day.
"You have to keep in mind that he missed the first week of pre-season so his fitness level was lower than the rest of the team. That already means you have to be careful.
"Van Persie has also just travelled for 30 hours and he had a nine-hour time difference. Normally the body takes a week to recover from that. And still, despite these difficulties, they immediately over-trained him because they want him to catch up on the rest of the team. Moyes literally said it in the media.
"You don't have to be Einstein to understand that is gambling."
Verheijen is no stranger to handing out criticism to British coaches. Last year the outspoken Dutchman branded England's preparations for Euro 2012 as "amateurish and prehistoric", in reference to the manner in which the Three Lions dealt with injuries to Gareth Barry and Frank Lampard.
Having labelled Moyes a "dinosaur" following his appointment during the summer, Verheijen has once again attacked the Scot by questioning his technical ability as a football coach.
"If you look at the track record of Moyes at Everton, in the nine pre-seasons that he did, he had seven or eight times an injury crisis in pre-season followed by a slow start to the season. Clearly that pattern repeated itself at United. The planning and conditioning part in his coaching is prehistoric.
"The second problem of David Moyes is his technical awareness. If I look at the Manchester United games, I don't think he's technically the best coach in the world to say it in a polite way."