Reading striker Dave Kitson was dismissive of the competition this week, while some Premier League teams fielded weakened sides for their third round clashes.
But Ferdinand is adamant that football's oldest competition remains among United's priorities this season.
"You hear some funny quotes coming out from some people saying they don't care about this competition," said the England international.
"I don't know how you can turn your form on and off for each game.
"You want to win every day in training, let alone a match in front of 30,000 people.
"Manchester United go into competitions to win them.
"It is just a natural winning mentality to want to go out and win every game you play. Most players are like that. I have not got it inside me to say I want to win this game but not that one.
"If you do that, you won't do yourself justice, or the team, the club or the fans."