Robin van Persie and David Moyes have reportedly clashed over the new Manchester United manager's training methods, with the striker believing the new heavy workload is to blame for a recent spate of injuries.
According to Goal.com, Van Persie has told friends he is not happy with the greater emphasis on running and endurance that has been brought to training since Moyes took over after the retirement of Sir Alex Ferguson.
The report says the former Arsenal captain and the former Everton boss fell out in the run up to the 4-1 derby humiliation at Manchester City when Van Persie was ruled out with a groin strain.
It says that Van Persie believes being over-trained was behind injury ending a run of 90 consecutive Premier League appearances and that the new regime brought in by Moyes does not suit his particular style of play, body shape and the fact he is now in his 30s.
Not only that, Goal.com also say last season's Premier League Golden Boot winner is unhappy that Moyes did not opt to keep Sir Alex Ferguson's assistant Rene Meulensteen at the club, as he felt his compatriot's training methods had a lot to do with keeping him fit.
Van Persie's goalscoring form over the last three years has been remarkable - he finished top scorer in the Premier League for the past two seasons - and this has largely been down to the fact he has been able to play regularly.
After joining Arsenal from Feyenoord in 2004, Van Persie was blighted by injury and rarely would complete a significant run of matches in the first team due to some knock or another.
The 30-year-old's reported unhappiness at the current training methods being implemented at Manchester United is likely down to the fact he fears falling back into another cycle of injury after injury.
Moyes revealed Van Persie was a doubt for Saturday's Premier League clash with Southampton due to calf and toe problems.