David Moyes pre-season handling of Robin van Persie has been called into question by a Dutch fitness specialist who has worked with several leading clubs and was assistant to the late Wales manager Gary Speed.
Van Persie was withdrawn at half-time during United's friendly in Japan on Tuesday because he had experienced tightness in his thigh. Moyes said the substitution was precautionary and that he expected the striker to be fine.
However, the new United manager was still subjected to stinging criticism from Raymond Verheijen, who has worked with Barcelona, Chelsea and Manchester City among others and has a reputation for being outspoken.
Writing on his Twitter account, Verheijen noted that 'Moyes had previously said United had 'overtrained' Van Persie (right) at the start of pre-season'.
He wrote: "In Sydney Moyes said: 'We've overtrained Robin this week to build up his fitness'. (In Japan) he picked up muscle injury. It really makes you wonder how these pre-historic training methods can still take place at the highest level.
"The only way to solve this problem in Jurassic Park is to improve education of these dinosaur coaches, fitness clowns & scientific cowboys. All over the world in pre-season you see the pattern 'overtraining-fatigue-injuries'. Always avoid accumulation of fatigue in pre-season.
"But as long as most dinosaurs are still in denial and ignore how things develop in other countries, nothing will ever change. Obviously, players like RVP should learn to protect themselves better against 'overtraining'."
Moyes admits he will be forced to rely on Ryan Giggs to guide him through the early stages of Manchester United's Champions League campaign after admitting he has much to learn about the competition.
Moyes, who suffered a 4-2 aggregate defeat with Everton against Villarreal in the 2005-06 qualifying stages, will experience the Champions League proper for the first time as a manager when United begin their group stage fixtures in September.
Having taken charge of Everton on 26 occasions in Europe, Moyes was unable to go beyond the last 16 of the Uefa Cup or Europa League, but he takes charge of United aiming to build a squad capable of winning the European Cup for a fourth time.
But while conceding that he will go into the Champions League as a relative rookie this season, Moyes believes that player-coach Giggs – who has more than 150 European appearances to his name – will be a crucial sounding board during the group stages.
"The Champions League will be a thrill, but I'm going to have to learn a lot quickly," Moyes said. "That's where I'm looking to the likes of Ryan Giggs and a few players around me for the things which I need to be told about.
"It's not all about the playing side of it – I've been in the Champions League (qualifiers), watched loads of games and managed in the Europa League – everybody has to start somewhere."
With efforts continuing at United to lure Barcelona midfielder Cesc Fabregas to Old Trafford, Moyes, in Osaka ahead of tomorrow's friendly, remains hopeful of adding to the squad he inherited from Alex Ferguson before the start of the season. But having admitted that he must win a trophy quickly as United manager, Moyes is determined to add to the club's history of success in Europe.
"The history of this club is immersed in Europe and I think to win one of the big European tournaments would always be seen as something special," Moyes said. "Winning your own domestic league is very important, but winning the Champions League has become very important, for the country and the Premier League.
"I think the year when Manchester United and Chelsea played in the final, everyone connected to football in this country stuck their chest out.
"It was the German teams this year, in the past it's been the Spanish teams. I genuinely think there's a swell of pride from our country that we want the British teams to do really well.
"But I've got to say I'm really looking forward to it and hopefully we can do well this season and I do think it's a much more open competition than it has been in the past.
"Even from the draw – if you don't get a particularly good draw it can become a struggle whichever part of the world you're playing in now." (© Daily Telegraph, London)