"When I was reading about all these things, I did wonder about what impact it would have when all the players' wives were together," said the United boss.
"If Rio felt that was an encumbrance on the team, I am sure Fabio Capello is quite well aware of it."
Having family so close, for the entire duration of the tournament, seems at odds with the professional approach required for England to reach their potential.
It seems unlikely Capello would countenance a repeat if, as has been reported, England base themselves at a plush hotel between Port Elizabeth and Cape Town should they reach South Africa 2010.
"To succeed in football you must have a certain discipline and make certain sacrifices," said Ferguson.
"That has always been the case here."