Sir Jim Ratcliffe reportedly identified Casemiro as an example of questionable recruitment at a meeting with the Manchester United hierarchy in March.
The billionaire, who is seeking a 25 per cent stake in the club for £1.4billion, believes the club could build its squad more shrewdly, as reported by The Guardian.
United's imports have been hit-and-miss in recent years and they have topped the global spending table for the last decade, splashing out £1.67bn on new stars with little to show for it.
Erik ten Hag has grown frustrated with the recruitment process at Old Trafford, according to Mail Sport sources, and would welcome a revitalised approach brought by Ratcliffe.