Ferguson says the club have looked to bring in more players from the continent in recent times.
"Our scouting there has increased," Ferguson he told the club's Inside United magazine. "We've got an operative in Mexico, two in Brazil and four South American scouts now.
"Quite frankly, they do produce. You see Antonio Valencia - he's as tough as nails with great discipline about him. The South Americans love playing football, it's just in their blood.
"The three Brazilians - Anderson, Rafael and Fabio - love it and are first to training every morning. It's a breath of fresh air."