Ferdinand missed the games in San Marino and Montenegro to fulfil his strict fitness regime.
But former United and England team-mate Butt, 38, said: "It's easy to say Rio's let his country down or he doesn't want to play for England. But that is not the case.
"He is passionate about playing for his country.
"He manages his body the way he does in order to play games for Man United.
"If hadn't done that, then he wouldn't have got the recall anyway."